Weather it is a major concern depends on how worn, if you could get a feeler gauge down the side of the key and let us know, that would help.
The float bowl gasket can sometimes be comfortably saved, it depends on the material, and care used. often it cannot though, so yes. to speed thing up, they are in the shop right here on the forum!
there are a few issues that could be effecting this, most of them lie in that bowl, so it is probably a good idea to give the carby a good clean up!
