Back around 1990, I was able to remove the tank sticker from my '69 Corvette...
In the photo attached, it has been reduced in size from several megabytes to the 138 kb to fit this site's requirements. After some digital enhancement the original was fairly legible... even with the large red-dish glue discolorations on it and I was able to discern the equipment and options on it.
PS. I don't recall what chemical I used to successfully remove it, but I know I was very careful with it and spent quite a bit of time and tried several things. After removing the sheet, I cleaned and sealed the inside of the tank and re-installed it; it still is functioning today.