After reading info on different sites and considering copper niles badge with serial number, beige - weak chocolate milk paint inside shells (most pronounced on inner hoops near edges), zoomatic snare, large tone control knobs, stick-saver rims, and set-o-matic tom mount - I am pretty sure I am looking at a range from 1968 to sometime in 1971. Need help with another clue please:

I have attached a photo of a set-o-matic mount base (NOT mine). My base does NOT have the logo on it. In what year and/or month did they start using a base just like this one without the logo. I have seen catalog photos from 1968 with the logo but no definitive dated photos of base without logo.

Thanks to all interested.