Sadly Dad died in June and we're slowly going through his things. In a drawer was a pile of tax discs.
EUD 996 Believed to be a BSA Bantam
LBW 788 Believed to be a Shooting Star
And the one that isn't a BSA
LUD 24 Royal Enfield Clipper.
None of these show up on DVLA but they could still be sitting out there waiting.