The 1980 rifle isn't a BSA Shirley produced type - if it is a Mk1 body it is probably a Faz., yet the serial number (haven't looked to see if it is on the list - it's academic anyway) is for a BSA Shirley rifle of 1944 mfr.
Now I realise who the seller is I must say I find it hard to accept that he is knowingly behind this. I don't know him well, but I do know him, & I think it is far more likely that he has been sold a pup. He has shown me several unsolicited kindnesses when we have had dealings over the past few years.....