GM Records Canada vs USA - Anyone know why?

[davepl]

If you're not already aware, GM Vintage Vehicle offers complete information about any vehicle built in Canada (usually at the Oshawa plant), at least as far back as I care about cars and truck.

My understanding is that some US Pontiac records are available down here, but nothing for the rest of the major GM brands.

Does anyone know the story of why? I mean today no one cars how your 1996 Cavalier is optioned, so I can see why they just may not have kept them, but Canada did, so...

I can't help but wondering if there's not an old IBM System/360 tape in a basement with all this data. I've heard stories about a fire that seem apocryphal, but nothing concrete.

Has anyone ever heard a likely story as to why build sheets and build data aren't available for 1960s US-built vehicles?

Thanks,
Dave

PS: FWIW, when I started at Microsoft in the early 90s, I tried to track down the source code to the Commodore64 BASIC interpreter, and never had any luck. So it's not news that things just get lost, but I'm really curious.