I have a BSA s/s shotgun, I was given it years ago by an old guy who was on his last legs. None of his family shot and he couldn't bear to hand it in.
It's fairly battered and I have always just assumed it was an old heap but recently I was told, as an English made gun it was worth money.
I have no idea about shotgun values, is there likely to be any truth in what he said? The gun has definitely had a hard life though