"Look under the back seat".
That's what i have always been told the build sheet was put at from the factory. I think i found what is left of mine, but it is under the drivers front seat. I put a mirror under the seat and saw a few pieces in between the springs. Looks like it has disintigrated over the years.
Even if it were still in one piece, you would have to take the front bucket seat out of the car to get at it. I have never had the rear seat out, so maybe there is one under there too!...
yeah, i know, wishful thinking.
If i could spin the clock back to 1972, i would have put the build sheet under glass in a frame and mounted it on the wall over the fireplace!!!!