Given the ST-1 custom kit arrived today, I was finally able to grab the tuners and bridge and put this together.
Let's keep with the "successful failure" at this stage.
The tuners were no major drama to install beyond having to enlarge the holes a little.
The bridge went on with no major issues after a quick measure. I wish I'd thought of measuring before I stuck some copper tape down to earth the bridge. That's a bit of a mess that still needs a clean up.

The bad:
I need to shim the neck. A lot. Given I'm working with so much plastic, I'll just make a plastic shim to fit in. With the bridge action set as low as it'll go, I've got about a 10mm gap at the end of the fret board that I need to reduce.