unknown dingy

[gregJ]

I am restoring an old British dingy for the local scouts. It is about 12 feet long with a tall unstayed mast right in the bow and a single sail (ie cat rigged). The sail insignia is 'MK' with the 'M' and 'K' joined together with a sail number of 121 (there must of been a few built). The boat is in good condition, made of mahogony ply and I would guess about 50 to 60 years old.

Any suggestions as to class/type would be most welcome.