Finally made it to the storage and dug out a set of beta molded parts. Thought I had several, but only found one.
Picture attached.
Production parts were one part for the top shell and one for the bottom shell. Took a while to find a company back in the 1990s that could handle vac formed extruded EPS sheet as large as the SR-71 model in one piece.
Having found them, I do not think I would fix Aerostadt's model by using them, after looking at the pictures, especially now that he has separated the shells. The best way forward would be to simply put the cracked parts back together carefully with a thin film of 5 minute epoxy, one part at a time. if the joint is carefully wiped with alcohol after joining, the repair will be nearly invisible. Any minor crumples can be filled with lightweight spackle and touch up painted with black acrylic craft paint.
I did offer them to Aerostadt first. If he passes, I would be willing to sell them to mickeyd if he thinks they would work for his repairs. I was thinking 10 bucks plus shipping would be fair......
Should be easy enough to re-attach the elevator servo to the mixing tray assembly. However, I would strongly consider a modification to the radio installation.
A near fatal flaw on the production R/C SR-71 was the use of simple mechanical mixing and stock control horns and servo arms that, as shipped, gave far too much roll control for a new or beginner R/C pilot. When I left HobbyLab after the free flight model was being shipped, the plan for the R/C version was to use an adjustable on board electronic mixer with the inexpensive Hitec 3 channel radio system to give less roll authority and good pitch authority, so the average guy MIGHT be able to handle it. (kind of a pipe dream, I know.) The R/C guy involved after I left ended up using a simple sliding servo tray instead to get the needed elevon mixing, due to price point pressure. The R/C model as shipped is pretty tough to fly well, even for an experienced pilot.
If you happen to have a modern TX with elevon mixing and dual rates and an associated RX, the best fix would be to ditch the sliding tray and simply have one servo hooked up to each elevon. Mix as needed and set the rates to a small amount of roll and a moderate amount of pitch.
If you must use the stock TX that came with the SR-71, play around with the aileron servo arms to reduce the roll throws to make the model easier to fly with the simple TX and sliding servo tray.
The stock R/C SR-71 was a little overbuilt and overweight for 24mm motors, but we flew early production prototypes a number of times on F25W motors, which was pretty exciting. Right at the edge of foam flutter. I never tried it on a G40, but the guys after me did and thy reported to me that it typically reached the "speed of foam" and fluttered apart during boost. They also flew production models on F25 motors with few issues.