Build sheets mean a lot on a Nova SS after 1968 or a RS/SS first gen Camaro as it represents a substantial increase in value. The factory didn't mark the VIN and often overlooked the SS option on the trim tag on these cars; so finding documentation to support the claim means money. This is why there are people willing to sell you a build sheet or a window sticker and a stamped trim tag with any options you want on it.
My claim to fame was taking six cylinder light weight econ cars and dropping in the biggest baddest motor I could build, lightening the car even more, and then holding it up with the beefiest suspension parts I could find. No SS cars were harmed in the making of these Super Sporty cars and no decals or SS trim pieces were wasted on them either. My idea was to try and pass a first gen Camaro or a Nova off as a 307 with burnt out glass packs despite the widest tire I could stuff under or inside the rear wheel tub.
I found build sheets all the time as I ripped out the insulation and scraped the calk out of the pinch seams to remove every ounce of excess weight. But since I was starting out with a 307 three in the tree to begin with, and not the over priced SS model no one cared. I raced at NHRA sanctioned strips myself but many of the cars I built raced on the street against factory SS cars that never stood a chance against the cars that I built. That just drove those SS owners to my shop door to build them a bigger badder motor, but without the weight reduction or the improved suspension needed to plant the added power, so I had a steady stream of people that had their ideas of what they wanted throwing their money my way.
I also used to build a truck load of engines (literally I had a one ton truck I filled with six or seven SBC or SBF motors that I had done the worlds cheapest rebuild on to install in used cars for car lot owners). They routinely removed all of the factory documentation that the original owner had saved in the glove box along with all of those oil receipts proving maintenance and burned them in a 55 gallon oil drum behind the office. Why because they didn't want the new owner of the high mileage crate that was being sold as a low mileage (only driven on Sunday) used car after replacing the brake pedal pad with a new one plus my recently installed rebuilt motor and after the speedo turned back 90,000 to 100, 000 miles (this is very hard to do by the way) to complete the barn find aura of these very used cars.
The dealerships also removed the factory documentation on trade-ins, simply throwing them in the trash to prevent new owners from contacting the previous owners to talk about their car's past history. No rebuilt engines in these used cars as they kept only the good low mileage cars and sent the clapped out high mileage cars to auction for the used car lots and auto recyclers to bid on. Only rebuild motors these cars ever saw was a steam jenny removing grease and grime and a fresh coat of engine paint to cover where the high pressure steam had blasted the oil stains off right down to a bare block.
Every one wants to find documentation, but there was so little left after being sanitized by reselling the car so many times.
A happy and prosperous New Year to one and all!