"The cabinet was very banged up. We removed 3mm of ply off both sides of the headbox and re applied a nice new peice so we have no nicks or damaged edges. We also did this for the front door."
Why not just replace the entire panel of Ply in question? It's easier, it's a stronger finish, it's going to fit better and there'll be no issues down the track. Trying to remove ply one layer at a time is very difficult if your objective is to acheive a flat workable surface ready to receive a new layer of ply. By the look of the hack job being performed on this cabinet then I don't think it would be to difficult to spot his workmanship on the finished product.
Maybe this guy should take a short woodwork course before attempting his next cabinet restoration. I'm sure he'd be happier with his finishes and with less effort.
