thanks tony
I attach the sheet metal with gluw to the wood frame and use big head nails on the corners when I have beaten the metal around the corners then when all the metal is on the bodyframe I put metal strips on the front and back corners of the body (see the circels in the picture) these are screwed on.
originally they only nailed the metal on, I found many old nails in the wood and some screws.
I will make some pictures as I get to it.
cheers jaap