Aluminum pads or a universal adapter plate is one thing. I wouldn't consider using solid aluminum bearers. FWIW, when PW built his 2nd B-17 stunter for the Y2K World Champs in France, he used CF beams for all 4 OS .15FP's. One engine always ran goofy, which Paul fixed by sawing off all the CF beams and replacing them with regular R/C mounts of glass/nylon construction. Apparently, vibration is one thing, but vibration damping is another. Maple should absorb vibes better.
About aluminum heat treating, if it says, for instance, 2024T351, that indicates it was heat treated at the aluminum factory. If it's a single digit after the T, then it was done afterwards. I'm not sure if it really makes a difference, but an FYI.
The SIG LG's, blanks, etc., are said to be 6061T6, because it isn't too unhappy to be bent post-HT. At least some of the Brodak gears appear to be SIG items, from squinting at the Brodak online catalog. It's possible to determine the alloy and HT spec by a combination of Rockwell and
Eddy-Current tests, without damaging the part. Another FYI, 7075 is heavier than 2024, which is heavier than 6061...more copper in the alloy. It's enough to be very noticeable.
I sure miss Boeing Surplus. The last time I went there, I looked at a bin of nice pieces of Ti, but I didn't want any. I moved on to look at other bins, and noticed a guy pick up some of the Ti, and put it in his cart, like he was going to buy it. I asked what he was intending to do with the Titanium, and he put it back like it was rotten fish.
Steve