I have a big old floor jack that I got from a BIg -O that went out of business. It started acting up..I had to replace the leather seals cost me 3 bucks at the local hose shop. works excellent now.
you never know what it is...sounds like a cool car you would not want someting to compromise the integrity of the filler, also I would get the undelying metal as close as possible just use a skim coat as little as possible. I would remove it.
That is awesome....I had a license plate frame made for my 75 Cadillac that said 500 Cubic Inch Global Warmer....I got a few dirty looks from the tree huggers.