I'm brand new to this forum, and this post has caught my interest very much, because of the inserts being shown - as I just placed an order for an older Mobius Megarar Toneweaver which has had a very interesting modification done to it, and I wondered if the inserts were original or if they were a mod as well.
She be seen here via the original Reverb ad: https://reverb.com/item/19358307-megatar-toneweaver?gclid=Cj0KCQjwpsLkBRDpARIsAKoYI8wnSs14p3h6aEzjcp1uimjsnX-c-DMX3QsRqMUSAchpi2c84dR3kQAaAnR2EALw_wcB&gclsrc=aw.ds&pla=1
It's a fascinating idea, and for me was the major selling point - as my days of standing with a heavy instrument strapped to me are long gone.
I saw this - and I wasted no time buying it - as it was set up exactly the way I wanted it, and while I probably paid way too much [I paid the asking price] there was no way I was letting that baby go, again because the peg modification - and the way it's set up from a tuning standpoint - were both exactly what I was looking for.
I'm glad to be a part of this forum, as there was no way I was joining the other one out there, no way !!
My other instrument is a Warr Phalanx series 12 string - which also has a twist: the guitar half on top is in reciprocal tuning - it's not like how all the other Phalanx - where it's set the same as the bass strings, so I'm trying to figure out the correct tuning as I'm thinking 4ths for the 6 bass strings - and maybe 5ths for the melody strings, with the exception of the highest pitched string, but anyhow I'm just happy to be here.
My Megatar should arrive towards the end of this up coming week, if you are interested further in that peg set up - which picks up those same two inserts - I'll be happy to oblidge.
I hope that link will work, because there's some excellent pictures there, and I believe the rear serial number cavity may even be signed by the man himself ??
As for drilling extra holes to install threaded inserts, I don't see why not but make sure the right drills are used, as you don't want to damamge/split the wood by using the wrong kind of bit, also if you are not going to take the neck off that Warr, make sure you use a special bit that is set up for - this might be the wrong word - bottoming ?? - meaning one that just has the flutes but not the point.
I'm also not sure how those inserts are installed, if they are bonded/glued in, or if it's a press fit... or maybe some other means.
Anyhow, cheers.... and I hope that I have perhaps presented an idea or two here.
Big George W
East Derby CT
WARR, Mobius Megatar , Syme, KYDD, Ovation , Steinberger , Tune, Schecter, Musicmakers [lots !!], Ironwood Stick 
digitech, T.C. Electronics, ART, Lexicon, GK, Markbass, EA, Bag End, Guild/Hartke, SWR, EV, Radial, Furman
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