I just bought a 1968 vert. I was told the build sheet is still on the tank should I remove it or not?

You need to drop the tank to remove it and that is a job. I think most people take them off and try to preserve them. Otherwise they will eventually be totally destroyed. Some people laminate them, but I'm not really in favor of that method, as its difficult to prove that the laminated one is really a true original. But there are pros and cons to that as well.

Mark

I took mine off of my '68 a few years ago. I put it in an album. Later when I figured what a computer and scanner were, I scanned it and put the scanned copy back on the car. Just saving the old original one.
The paper on them is very cheap and gets brittle with age. You may want to take a digital picture of it before you try to remove it. Mine is so fragile right now, it won't come out of the album.