Anyway, something is happening, but with the design of the machine, with the boards being in the bottom of the cabinet, it would seem that the production is severely hampered without the boards to put in first, then everything else gets built around the steel box etc.

All playfield cables connect with easy disconnect plugs right to the back of the electronics box (ie. no plugging stuff directly into boards). Plus, the whole electronics box is held down with simple rubber ties and pops in and out of the cabinet with ease. So no, the location of the boards has nothing to do with having to wait to build.