Help With Moses neck install

[wombolombo]

I just got a great deal on a used Moses neck...and that's where the issues lie.

The neck came with the smaller threaded inserts installed in all but one hole...and the hole without appears to have had the insert removed (in other words, I think it's too big to put a smaller insert back into it). It did not come with the screws for the smaller inserts. It did come with the 4 larger threaded inserts and screws.

The shop I took it to is stuck on what to do, and is ready to give it back to me...unless I can come up with a solution.

Here's what I'm thinking of doing...
Going to my local h'ware store and buying 3 of the smaller-sized screws for the inserts that are already there, and having him use the larger insert for the empty hole.

Thoughts? Better plans?

Thanks for your help...

FWIW - this is a project bass, so it's already got a lot of mismatched and weird looking parts. I'm going for performance, not beauty!