Well, I feel like a real machinist! I spent $300 on tooling and materials, and about 40 hours to save $350 for specialty hardware for my Cobra (oh, and I probably have a couple more hours polishing the stainless so it kinda looks like chrome).
Anyway, thank you for your help. I almost made a sine vise, but my little Palmgren vise's rails were too thin for 1/4" bolts, and I didn't have any smaller hardware handy. After seeing Winegrower's, however, I've added a sine vise to my list, as it would have made easy work out of today's task (and saved me probably 5 hours).
I ended up taking 2 aluminum bars, putting a couple layers of masking tape between them, and boring holes at the right angles. To drill the correct angles, I used a 3/4" drill on one side of my 6" Kurt vise which gave me close to the desired 7.3º. For the 10.7º hole I machined a spacer block out of delrin to prop up one side 1.13", giving me close to the 10.7º angle I needed.
Here are the stand-offs:
My next question is how to get a mirror finish on 303 stainless, but I'll post a separate thread on that.