I'm rather military knowledge ignorant - but I'd suggest that today, there are safety and technical standards that can't be avoided.
Maybe even ergonomic standards.
In other words, a builder today has much more complexity to incorporate, and the complexity must be engineered into the product.
Just take a look at the auto industry.
I'll bet that in 1940, a crew of 3 trained mechanics could dissassemble and reassemble most of an automobille without, say, stripping the engine block apart, in ONE DAY..
But today, I'd imagine it would take 3 trained mechanics a week to dissassemble and reassemble my 2003 dodge truck.
M. D. Vaden of Oregon http://www.mdvaden.com