Quoted from TaylorVA:
I think it is great that they are being offered up, I am just questioning the COA and want to know how they know these are One of kind items. From what you are saying they most likely are not, which definitely will affect value IMO.
At this point in time they are likely one of a kind (or at least the only one known to exist) but when these were done there were likely a dozen or more copies of any given blueprint. Original would likely have stayed with design department, copies would have be sent to production meetings, machine design department, out for vendor estimates to get production quotes, etc. They do not pass original designs around for all of this they send copies which would be returned to the drafting and design department for revisions.
When OP posted these I wanted to verify he wasn't making copies of these copies and he said he wasn't. That isn't saying there are not other copies in files somewhere else or even second copies of some of these in the piles of stuff he is working through.
When a company makes blueprints there are usually plenty of them for each original drawing. The question is if any of the others have survived. These are not like original drawings of playfield art or backglasses that typically bring hundreds of dollars. These are design department blueprints of sub assemblies and as OP stated above Blueprints are all copies - not the original drawings.
They do have value but I don't see these having a great deal of value beyond something kind of different to hang in your gameroom.