So it looks like somebody — I couldn't say who, of course — has put up a Butterstick CafePress store. There's only one design, and it looks like this:
Best of all, the $1 profit margin on the shirts will be donated directly to FONZ! Isn't that nice? Wouldn't FONZ be jerks if they sued whatever dashing man (or woman!) of mystery is responsible for this design? Of course they would.