How much did JC ask for an original converted fuel gauge?
I didn't know they offered them
for those who are not aware of the problem here is a pic of the raised needle
...pic... if you are stuck with using an aftermarket 12 fuel gauge try adjusting the bezel by gluing a gasket to the back of it
...pic... ...pic... it will give you enough room to clear the raised needle.
original 6v are on ebay, you could purchase an nos and use a reducer with it.