Match and upsize rear fuselage to VS holes for M4 bolts

The alignment between the holes (which are supplied for the original M3 bolts) in the rear fuselage skin layers is terrible. The mismatch with the VS M4 rivnuts is just as bad. This is made slightly worse by the introduction of the 0.4mm thick "washer" plate fabricated recently.

These holes and bolts are not structural, serving mostly to fasten cover plates. So all these problems were swept away by upsizing and recentering to 4.8mm