Got the 3 deck belts replaced, adjusted azimuth and speed. May have to do another speed adjustment, runs pretty constant, then drops ~25hHz with quick recovery. W/F not awful at 0.08-0.12. Hoping the speed 'dropouts' improve with some run time; wish this had an auto-repeat function.
The only belt I did not replace is the tuning flywheel. Not going to mess with the dial string unless I absolutely have to.
Azimuth was a tad out using an 8kHz tape; may be close to the limit on these heads, 10kHz gave a much wider lissajous curve, didn't bother with the 15kHz tape. I may break out the Nakamichi T-100, see how bad the frequency response is. Probably not worth looking at anything beyond that, I assume most adjustments I have on my Nak decks are likely fixed on the JVC. I won't bother measuring anything on the record head, this will be used for playback only.
Overall, the sound is pretty good. Seems like this is a much nicer unit than the PC-11; certainly better features, and more thought went into the engineering; i.e. separate phono & aux inputs, loudness control, the multi-position speaker mounts for use as a complete boombox, or as a standalone portable cassette deck. Overall a very nice unit!