FWIW - I was able to swap a pinch roller from an NOS SDT-11000 with one on a r700 and it fixed all errors I was seeing
Pinch rollers can dry out after a few years depending on the environment. The one on the r700 was concave so the tape was slipping - deck only has about 40 hours on it.
The one on Full Compass looks identical to the SDT-xxxx pinch rollers and the r500/r700
So this may be an option for you DIYers to fix high error rate DAT machine versus getting it professionally fixed ($20-30 part + 20 minutes or assembly/disassembly of your dat deck)