Oscar, I didn't sit around disecting my brother's accredidations and what he could legally do or not do when he had his shop some 30 years ago. As stated, he had several friends who worked for the local PD, so I find it highly unlikely he would blatently defy any of the rules and regulations based on his specific FFL, with the risk of getting locked up in the hoosegow. Considering these same individuals would occassionally shoot the same weapons, you'd think if they knew they were illegal, they'd have done something about it. You can be a trolling ATF agent all you want. My brother closed his shop back in the early 80's, and pretty much all his equipment and inventory was sold decades ago.
I don't think anyone is trying to discredit your brother.
I believe some are calling you a liar based off the statements you have made in the past and how your defense goes in a circular motion.
Still waiting to hear how he ordered and purchased an UZI for civilian purposes..especially since the local PDs didn't have them in the 70's. Find me another wikipedia link. I won't even explain the "Gun Range" circular motion.