I list the TC-651 Service Manual on my web site, but it is listed as a partial manual, missing the Part Number Lists, supposedly the parts not being available, whoever copied it left them out to save a buck.
That info is out of date, I do have the complete TC-650 Service Manual now, I just have to find which box and folder it is in.
The TC-650 Service Manual is available for $29. cash, check, or MO. shipped in conus or $30. shipped for Paypal to: slbender@gmail.com - to partially pay for the fees Paypal collects.
I also have many parts including a head assembly, pinch roller, VU Metters, motors, PC boards, switches etc. pulled from a working TC-650 that was dismembered for one particular part.
-Steven L. Bender