1975 gmc Indy truck

[1975gmcindy500guy]

Hi,
I have a 1975 Indy 500 promo truck
as far as I can tell my gmc was one of two built it looks just like the one in the promo add for that truck. I have a full press kit for it and it says that 200 replicas were to be a dealer installed sticker package but I found a sorce that said that they decided not to build replicas untill 1976 my great grandfather purchased this truck from the race when he was working in promotions. I belive it was the truck it the parade that drove the big bass drum for the perdue band.
Please help me find info on this all gm could tell me is they built a couple for the race and they had no record of repoductions being made. Does anyone have a official truck from 1975?
Dave
it's white with tan int. Factor buckets. And has almost all the options 2wd 350 turbo 350 and all stock all orig.