How do you:
1.) get your forward mandibles perfectly aligned with the rest of the ship?
2.) make sure they are dead-center and "locked in" at exactly 2 inches high?
You make a sidewall fascia plate that 'receives' and 'guides' your mandibles.
ABS Structural Flanges (SAF-24L to SAF-40L are the pieces to look at on Plastruct.com) from Plastruct with 1/8" channels in the center, along with a center spacer plain strip of ABS, and now you have a fascia plate that is a.) exactly 2" from upper to lower channel, which is, b.) exactly the width of your styrene mandible jaw pieces.
And that dead-center hole cut at 3/4" diameter? That's so you can do this:
So that once you epoxy them down conformally to the sidewall, you know for absolute certain that they are placed at the exact center point of the armature sidewall. See those white squares around the rest of the tubes? The ABS Structural Flanges will go "behind" those, obviously, but those are there to lend support/guidance to the rest of the mandibles as they get built above and below them. Those are acrylic cut from a lasercutter, and are also the exact width/height needed to have the 1/8" styrene mandible plates come out to a total height of 2 inches exactly.
The hardest part, so far, in all this, is now figuring out precisely how much/little to "trim" the inner curvature of the mandible plates themselves for an exact placement in terms of length. So I won't have pictures of the finished product until a whole lot more reverse-engineering with greeblies and with tip-to-tail measurements are made and I can come reasonably close to a total length of 170cm, or 169.25cm according to the Bandai conversion method. Right now I'm a little "long" overall, but happier to be long than short, because this stuff is basically the world's most expensive haircut -- it's a whole lot easier to cut it off than to grow it back.
Anyway, having a fair amount of fun and excitement as I get closer to the point of making some final decisions and commitments that require epoxy, and permanence, and then I can say I'm actually building the thing instead of endlessly researching it, which is what the last two years has mostly felt like.