Morris Minor Owners Club

Hi everyone,
After 12 years mostly uneventful and reliable motoring...
Can anyone help me locate a set of piston rings for my MM (USHM3) please?
The reference numbers I've been given by the garage are:
502-13/1G+020.
I'm told a single ring might do it but would prefer to have the set if possible.
I haven't posted here for years so I hope I've followed the MMOC rules ok.
Any suggestions and/or referrals will be very gratefully received.
Thanks,
Brian W.

Hi everyone,
Update: I think I may have found the ring set I'm after, so currently no help needed.
But my thanks to all who read my post, and happy motoring.
Brian.