Mark, any chance you got the serial number of this drum when you contacted the seller.

I just sent another message to the seller, but looking at the pictures, it appears that the SN is 156954, possibly from 1967-68, which makes sense given the chocolate milk interior. Still, given the small-knob tone control, I'd say 1967, although the seller lists it as a 1968. What do you think?

-Mark

I concur, Mark. I could not make out the first number but a 156xxx serial would be expected for '67. Chocolate interior and small tone control knob makes sense.