I just found this thread when searching for Nash JM-63 and pots. So I guess I'm a new member. Thought I'd post my impressions. And avoid that argument, heh.
I'm about two weeks into a new JM-63. It looks just like this one (altho I paid a good chunk less than that):
https://reverb.com/ca/item/2349926-nash ... serial-261" onclick="window.open(this.href);return false;
I used to have a Classic Players Jazzmaster about 4 years ago, and I sold it because I just didn't like the neck nor the pickups (no sparkle at all), and I didn't want a "project" (I have too many already). But because that itch wasn't scratched back then, it just seemed to grow. The reason I bought the Nash was because it felt the best in terms of playability at the store (and it had the most sustain). It was, truthfully, a little more than I wanted to spend (I was hoping to keep things under ~ $1500 USD including tax, which is 12% here in B.C.), but I still have another two weeks to return it if I change my mind.
In total:
+ Thus far, I think I've needed to tune it up maybe 2x. I'm very impressed with that.
+ The neck is the best part. Smooth feel and I love the way it plays.
+ The rhythm circuit modification (it works on all selector positions) is better. I actually like using this on the middle position, oddly enough, to get a smoother crunch rhythm.
+ It balances perfectly with a strap. I love that. The Fender reissues did not (at least on me...the sales person said sometimes they do, sometimes they don't...that seemed odd).
+ It seems using the Buzzstop does help with sustain. I'm not sure if it is helping with the tuning, as well, but it might be.
+ The bridge feels nice on palm resting.
- I wish the neck "relic" on the back went down further. It is literally the best feature on the guitar (in how good it feels) and matching it to a "look" of real wear doesn't interest me as much as smooth slides down past fret 12. I might look into doing something there myself. Maybe. I'm afraid, too.
- The Buzzstop does detract from the vintage look, imo.
- I'm getting a load of hum from the pickups. Like more than my Fender Baja tele. It seems to vary by pedal, however, so I'm not sure why that is. My keely tubescreamer doesn't seem too bad, but my two wamplers seem to kick the hum up crazy. I haven't taken the pickguard off yet.
- The neck and middle positions sound really good, but I'm not super happy with the bridge sound. They are lollar pickups. I guess I just want something that gets dirtier, but I don't want to put in a humbucker. I think the lollars are wound more for vintage sounds and not the big shoegaze wail / crunch I want to get out of the bridge.
So in general, I'm pretty happy with it. I think I'm gonna stick a Novak JM-180 in the bridge (not sure where to put the coil tap yet) to satiate my need for more grind, but truthfully I think I would have done something similar with any JM I bought. I'll check if it is shield well when I take the pickguard off.