I've done neck extension mods for the Ronin, the Kshatriya, and quite recently, the JinX. The thing about neck extensions is that if you are working with MGs or PGs, you'll run into the inherent problem of ABS plastic's semi-resistance to cement, and the problem of CA/superglue becoming brittle over time thus making it worthless for high stress/tension area repair work or modification.
The Kshatriya's Neck Extension was the "easiest" by far to pull off because of the frame construction and being made of PS. It was quite easy to simply saw off the neck, stick an ample-sized beam in between, and mount it on to the modified frame with a generous amount of cement (saturating the modified parts allow resin build up from the cement which reinforces the ABS/PS bond since ABS will also melt a bit when saturated enough with the solvent from cement).



