It turns out I need 148 holes drilled (not counting regular inserts) for lights and posts alone etc. Stuff really adds up after a while! On top of that all the inserts and special holes, ball-locks etc.
Quite a beefy design in other words!
I'm a bit nervous that I've missed or entered a digit wrong somewhere, but it's been so long without any progress so I'm thinking I'll probably be able to fix/drill a single or some holes on my own in case of emergency.