Uh, looks like my new roundie is a 1965, per RCA's Knob directory.
For everyone's benefit, I posted the RCA 62-66 knob directory here:
http://www.mebeep.com/pix/RCAKnobsCTV6266.PDF
Due to bandwidth restrictions, I'll keep it there until my limit is up. Feel free to post it on any website, no credit needed. I'll scan my other directories later - B/W, Color (rectangular) - and post them to the appropriate Forum.
Cheers