Specifications on Various Machines

Hi! This may be a little off topic, but I am hoping someone can direct me to my pot of gold! We are a machinery dealer. Consequently, we buy & sell used machinery, create specifications, take photos & post them on our website for marketing. We are having an awful hard time finding specifications on many machines. Currently, we are using the Big Book of Metalworking Machinery published by the MDNA (I think) in 1973. As you can imagine, the CNC area alone has just exploded since then. Manufacturers (on their websites) only post specs on their current machines, not on their recent-but-no-longer-manufactured machines. I don't want to clog down the whole forum every time I have a request for specs, so I am wondering if ANYONE, ANYWHERE knows any sources (preferrably free!) for anything from, say, 1973 to the present. Any & all hints would be helpful & greatly appreciated! Thanks!