Fitting pivots with M5 brass screws or my bronze pivot screws (Ref. 214) and threaded inserts in the wrest plank:
It's good to have a spare insert for practicing on; the idea is that you drill the correct size for the insert(6.3mm or 15/64" for the M5 brass insert), to the correct depth (9.5mm, ⅜"), the hole size determined by the insert diameter excluding the toothy bits which eventually are expanded into the wood to fix it in place. Then the hole is deepened using a drill (4.5mm) that gives a friction fit to the M5 pivot screw, 40mm? deep into the timber of the wrest-plank. Now, fit the black allen headed screw a few turns into the insert (no more than half way), set the insert over the hole and bash it in level with the surface; THEN, tighten the allen headed screw into the insert to open it into the hole, so the toothy bits bite into the wood and hopefully stay there. You could wipe superglue onto the pointy bits first, I've never done this but if the wrest-plank were walnut it might be a good idea. (When I had to do this as a last resort on a Kirckman of 1772 the wrest-plank had been knackered by several attempts of filler, dowels and bad screws so I soaked the hole with hot glue first)
The insert provides the thread, the lower hole the friction.
The levers will have been buffed to a shine, so they have some wax on them; this should prevent tarnishing, but a wipe with Jade oil or an equivalent when they are installed might be necessary before it all goes off to the owner.