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					Originally Posted by stephen crowhurst  I have an original plywood back for the gunners seat but that is only 3/8" thick so I take it that the two seats are made of different thicknesses of ply? | 
	
 I agree with you, Stephen. 
I have been using 9mm marine grade plywood.
When sourcing the Lift-the-Dot fasteners it will be necessary to know which post style and correct length.  If the board thickness does not match you could be making unnecessary work for yourself.