My best friend has a 3D printer, and came to the rescue. They would mount from the inside, since the surrounding bit would attach with some kind of adhesive. I took a few measurements the other day, and the "borders" were perfect for some 1/4" tape. I poked around Amazon and found some 3M mounting tape that should work well:
Here's the infills with the tape on them:
I did have to sand down a couple of the edges so they would snap in place properly, I just used a metal file. They installed fine, though the mounting bolts for the brackets on the inside on the edge toward the bike, make it so they don't quite mount flush. I could take them back off, sand the border on that end and try again, with new tape. For now they seem pretty good.
If anyone has these brackets and is interested in the print files, I can have him upload them.
Just a small project. I'm going to be listing the bike for sale soon, once I get the carbs reinstalled and everything runs and is cleaned up. I have a new bike and no room for two, sadly. If I have a hard time selling, maybe I can squeeze in some space somehow....and convince the boss.
S2