I'm a child of the 60's. I joined the Army as an adult in '87, so you can work it out.
That said, I wasn't terribly old in '71, but was well and truly walking...although I wasnt out of nappies until 1984.
A few years back I sold a motorbike and the chap turned up with a fistful of Scottish banknotes. I wasn't impressed, but a quick call to the local branch of my bank (Halifax) revealed thst while they weren't legal tender in england they would be happy to take it and pay the sum into my account, and they did.
So, while it may not be legal tender down here with the sassenachs they are most assuredly worth a lot more than the paper (technically a type of cloth) they are printed on.