theyre ar very few options
crosman did make a mount that would fit them and other models but it was for 3/4" bodied scopes and tbh not much better than the 2240 type ones
another company made a rail aragement that would clamp to the breech body (struggling to remember the name) but again now obsolete
these mounts i made for a benjamin gs397
if i were to scope one of my 140's i'd go this route or mill rails on the breech