No trying to spam here for the seller. But I ran across this on Ebay, looks like a blueprint for Soo Line Baldwin. Looked under the seller's other auctions and he has diagrams for NP and GN depots, locomotives and yards. They all seem to be origional.

Now for my question: How rare are these things? I'd suppose that railroads kept many copies of locomotives on hand. Maybe fewer copies of physical plant stuff like buildings and bridges.

But how many of these have survived archive purges after the equipment has been scrapped/torn down?