My first job was at a motorcycle dealership and they hired me mostly to clean up their upstairs that was absolutely chock full of parts they had basically no record or use for. Any inventory from say 1988ish was on computer database, but all the stuff from the 70s and most 80s was just on paper files and they never bothered to implement it into the computer database. Like you said, Im sure those treasure troves are long gong now.
its crazy all the stock stuff we just tossed is now worth $$$, airboxes, stock exhaust, headlights, etc. Not sure I understand this market to have 100% stock machines.