I brought this set home two weeks ago today. 13/16/22 with matching Jazz Festival. Since they are date stamped from late November 1966 I don't think it's too much of a stretch to imagine them turning up under some very lucky person's Christmas tree that year.
The cool thing is it appears that whoever had them lost interest fairly quickly and these were stashed in an attic or closet since then. They haven't been messed with in any way. They still had the original heads all around and no holes, black paint or other funny business. Other than some chips in the paint on the bass hoops these are pretty much as they left the factory. That makes them a rare thing around these parts and I felt obligated to snag them if only to preserve them in their present state...and also to brighten up my own Christmas x-mas3.
