Gday Rusty, I have two sons and they look at my old BSAs and laugh especially in front of their friends. They are only interested in Japanese bikes.
Now is the time to get those bikes from your brother the A7 at least cause by the time his sons are interested if ever it will be very hard to restore to original if at all.
I don't mean to be a vulture but it's true. I have a friend here that is going through the same situation. He is trying to get an almost complete original 1950 BSA from his lifelong friend but the bike belonged to his friend's dad who has now pasted away. His lifelong friend is not interested in the bike and wants to let my friend have it or buy it. The bike is sitting in a shed rusting away and the family keep saying they will do it one day but none of them are interested at all.
Here's something that worked for me. Back in the 70's, I found an old 1954 Harley Davidson sitting next to a man's vegetable garden behind his house. It was complete and stock but had not run for 20 years, and had been in the weather all that time. Faded and surface rust but still solid.
I stopped by one day and said I was interested in buying it. The man said "You'll have to talk to my sons, they're going to fix it up and ride it some day". Now I knew there was NO way these boys were ever going to come up with the shop and the thousands of dollars it would take to do it, so I made a pretty good money offer.
They got a little mad with me, and told me to get off the place, the bike wasn't for sale.
So I wen home and thought for a bit, and I rousted out an old Triumph chopper with a chrome frame that had been built out of bits, wasn't really licensable for the road and had no title, but it ran and made a lot of noise through its drag pipes. I had about $200 in this bike.
About a month later I rode back out to the house where the bike was, on this Triumph this time (it's all back roads from my house to theirs, no worries about no license or state inspection). They came out pretty stroppy, squaring off with me like "We TOLD you to stay away from here wanting that bike."
I started up the Triumph, revved it a couple times, and said "I'll swap you straight up for this one." Man did THEIR tone change. They suddenly realized that they could go from B.S.'ing me about how they were going to fix up this Harley, to actually having a bike to RIDE, and TODAY! They threw that Harley up on the back of one of their pulpwood trucks (they were timber cutters) and took it to my house right NOW, boy. I even got a title, they didn't care if they got one or not.
So sometimes you have to think outside "the box" ... !
Lannis