[Stratodog]

I did run into one reference to USAAF "70 mil" reticles being identical to USN "35 mil" reticles. That makes things confusing, because I thought that USAAF reticles were cataloged by crossing speed, weapon type, and radius.

Yep I agree, it can be a bit confusing. I did a bunch of research on this about 10 years ago, bought a bunch of old manuals on ebay. The USAAF 70 mil reticle was a 35 mil radius 70 mil diameter sight and was usually referred to as a 70 mph sight. This meant that you would use one "ring" or 35 mils of lead for every 70 mph of estimated target speed at a 90 degree deflection shot. A 100 mph sight (50 mil) radius was a lot more popular because the math was easier. I crunched the numbers a long time ago and I remember that the USN method came up with very close to the same amount of deflection using a different method. The explanation can get a bit blah blah but I can post some stuff I wrote at the time if anybody wants it. Anyhoo keep pressing on your doing some great work.