@Isaak570 posted:Sorry my English is poor, how can I say that, the head of the screw must be to the same level of the plate
No apology necessary! Your English is miles better than second language I'd attempt!
Like I said, I think your were basically trying to say the screw heads had to be flush or below the surface of the plate. I just figured I'd clarify that for anyone reading along.
Thanks a heap for doing all the heavy lifting on this and providing the drawing,