Those do help a lot, thanks Donnie...
I have three initial questions for you:
(1) You've very helpfully indicated that the space between the bottom of the head ring (aka flesh hoop) and top of the flange is ~9/16"... The flat black Mylar material that I'm using is fairly stiff and about 1/16" thick. If one of us cuts the width of this material at 9/16", will it fit fairly snugly under the posts? I'm thinking I may cut the width for you and then I can center the keyhole for the tuner mounting post more nicely, plus that way all you have to worry about is cutting the rearward and forward lengths.
(2) Will the tuner body fit between the first post (next to the neck) and the second post?
(3) If it does fit there between the first and second posts, when seated against the rim in that location, can you still read the tuner display (meaning, does the second post block the ability to read the tuner display)?
With my three main playing banjos I have mounted the tuner body as close to the neck as possible and also right against the rim, so it is sort of discrete, so it is also out of the way in the banjo's case and so it gets more concentrated vibration for tuning accuracy. On my Mastertone and on my CEB-5 the tuner actually fits between the first and second hooks and the hooks are small enough that the display is still easily readable. On my SS Stewart the hook spacing is closer so the rear of the tuner body rests against the first hook and the front of the tuner body rests on the second hook. This works out well too, but the tuner is not quite as discrete in it's location there since the front of the tuner is actually resting on the second hook. It's not a major difference, being only a difference in the location of the front of the tuner of about 1/8".
Because the Nechville's posts are so sutstantial, I suspect that if the tuner's body fits between them, the display is going to be hard to see because the second post will probably block the view...
Soooo, I'm thinking we'll run some length of the mount under the first post and possibly under the neck heel as you've suggested, with the rear of the tuner resting against that post. Then the mount will continue over the second post so the tuner display can be easily seen. Then the mount will continue and run under the third post, and maybe further, for anchoring. This will be sort of similar to how the stock mount would have worked; the big difference is that the tuner body will rest against the first post, so it will be much closer to the neck heel, more discrete and out of the way, and receiving more vibrations there.
I hope I'm expressing this clearly, if not, let me know and I'll try to word it better... (I would include some more pictures but my camera isn't attaching to my PC at the moment.)
Anyway, please consider this concept for the mount and let me know what you think. If it sounds reasonable for the Nechville, I'll proceed with preparing it.
Also, I'm thinking I'll prepare some similar blue Mylar material for you to use as a prototype for cutting the lengths and to experiment a little bit, then you can use that prototype as a model to cut the lengths of the black finished mount...
Sooo, some more questions: Since you have two Nechville banjos, are you intending to get another D'Addario NS Mini tuner for the second Nechville? Is the other Nechville's rim design the same as the one we've been talking about? If so, would you like to have two of these black finished mounts?
-- Don
P.S. Looking more closely at your pics, I can see that the "first post" is actually part of Nechville's innovative neck mounting system... Very nice. That said, I think the concept I'm suggesting still applies, even though the "first post" I refer to is actually part of the neck mount.