The 1040BCH and its later 105-420018-5 and 105-420018-17 derivatives use a plated steel housing with an aluminum inner handle. The mounting screw posts are in the same horizontal plane when viewed from inside the cabin looking outward. The door lock cylinder is mounted in the aluminum inner handle.
I cannot pin down exactly 'when', but for an interim period that I believe to have spanned from about 1972 to about 1978, Beech used, on the front cabin doors, what they termed an 'improved' exterior handle made by Hartwell (the H2532-13). Unlike the 1040BCH, the Hartwell handle has the lock cylinder mounted in a hole adjacent to the movable part of the handle. This same Hartwell handle was used on the large and small baggage doors of the planes beyond the reversion to the 1040BCH-style handle. As a result, the 1978 and later 19/23/24R/76 typically have the 105-prefixed handles on the main cabin doors, and the Hartwell handle on the baggage door.
The 1040BCH (and later 105- prefixed) handle is plated metal, but has several undesirable aspects. There is a spring crimped into the handle on each side; they often break. The metal appears to be nickle-plated, and the plating rapidly fails (resulting in rust). The overall quality of fit and finish is simply miserable. These handles are hard to find new. If you do find one for sale from Beech or one of its affiliates, in half those cases what you will find in the received box is a clone handle made by Wag Aero. This includes boxes received directly from Beech, with the paperwork. So much for the quality control financed by high parts prices and enforced by the FAA.
The Hartwell is no better; if anything, it is worse. While it looks like metal, it is a metalized plastic (low-temperature vacuum-deposition plating). Only the sliding locking bar and the movable handle portions are really metal. The plastic housing is highly susceptible to any kind of oil or grease; only powdered graphite is safe to use as a lubricant. The parts are retained by small pins embedded into the plastic; this includes the knurled inserts that retain the mounting screws. All of the plastic surrounding these parts cracks and breaks away with time. Even the slightest extra effort to pull open a stuck door results in the handle breaking through the plastic body at the inner end.
These handle styles are NOT interchangeable. The primary reason is because the mounting screws are not in the same location. While in some cases new holes could be drilled through the inner latch assemblies, in many or most cases that won't work. The later 105- design relies on a press-formed washer area, on the mounting studs, to make the interior latch assembly work properly. The Hartwell style handle does not have these lugs.
AEC makes the only decent handle, and it is a replacement only for the Hartwell-equipped doors. Their handle is 100% machined aluminum and stainless steel. It even has SS Heli-coils in the mounting holes that are machined into the aluminum body; and unlike the Beech replacement parts, it comes with the mounting screws and a lock cylinder. While at $350 is it not cheap, it is almost half of the Beech price for their plastic junk; and it should last the remaining life of the airframe. I wish I could help make a comparable unit become available for the 1040BCH-equipped portion of the fleet, but that's unlikely to happen.
I have become pretty disillusioned with the PMA parts process and the results of past efforts. I have had multiple suppliers tell me that obtaining a PMA will cost them $15,000 to $25,000 per part. Can you imagine how many $50 small baggage door seals AEC has to sell, to recover $15,000 in up-front costs, even when I have gifted them with all the specifications, drawings, applicability information, etc.? After maybe 300 seal sales, they can cover the PMA paperwork costs. Then they have to cover the engineering costs of dealing with the production testing, initial stock production costs, and some actual profit? And they have sold maybe 20 units since these seals were introduced, half of which were bought and paid for by me, for KLUX shop use? While I find Home Depot foam rubber on most of the baggage doors that show up at KLUX, with their sprung hinges, latches, and frames?
Then there are all of the folks who simply know what a plastic part should cost. Who have evidently never actually had to spend $6,000 for a chromed mold that is suitable for any level of production volume on a quality part. Or who have never bought a new car door seal in 40 years. Or who have never actually obtained a spring production quote from someplace like Atlantic Spring or Century Spring, on a product that will actually meet the Beech specs (in order to become a legal PMA part).
We have beaten up these pages before on why vendors such as AECI do or don't deserve support, or what they should be doing differently. I have also described what they typically go through in order to fund a project, with each new parts product having to be self-sufficient via its sales volume. No new product can afford to be 'carried' by other products, or it should not have been produced (insufficient market demand). In most cases, when an outfit like AEC makes a PMA part available, it is only because they believe that there is a defined market segment and marketing vehicle available for the product. In our case. BAC and its members. If they had to spend many additional thousands of dollars in broad advertising efforts through the aviation media, to such a relatively tiny potential market in terms of airframe counts, they simply would never proceed at all. So to think that AEC is failing to move product because they are failing to aggressively market their products, is simply a failure to understand the process itself. If they can only sell 50 door handles per year regardless, how could it makes sense to have to double the cost of each handle because of marketing overhead? These things aren't Big Macs and Frosties, in their millions.
I undertook past PMA efforts with AEC (and others) because of a perceived demand for these key parts within the BAC membership, coupled with the very high Beech pricing on the parts. In most cases I have evidently mis-judged the pent-up demand. For example, I have finally just sold the last of a batch of aft ballast weights, which Beech agreed to make for me more than two years ago. I had several thousand dollars tied up in these parts, thinking that the expressed interest meant that they would all sell within months. It took more than two years. That's the kind of thing that AEC is dealing with, but with far more expensive overhead involved.
I know that none of us can afford to buy every single thing that we want. Nor can we all afford to buy every spare part that becomes available, to stockpile them against future needs. But there also seems to be quite a large disconnect between previously expressed interest versus actual purchases of newly available parts. Robin at Power Flow and Laminar Flow has seen the same thing happen with exhaust systems and wheel pants. So at least in my case, and particularly in light of my current circumstances, pursuit of more PMA parts for our BAC aircraft has taken a relatively distant back seat in my priorities.