I think you may have hit the preverbial nail on the head. Having a punch set would be way more practicle in an assembly shop where you have to make darn near everything from sheet stock. Several of the sheffield blades that I've disassembled have piviot holes that look to have been struck with a chisel rather than drilling the hole. Having a raised washer would deffinately help with alignment issues.
By Jove, I think you've found something Baron.