i have a fiberglass shower base that is leaking. The only identifying marks being on the drain body it says Casper industries. the black rubber piece slides between the drain pipe and drain body seems to be a Fernco SD 200 or SD 210. it looks old and probably needs to be replaced. When i pulled out the rubber gasket you can see light coming between the drain body and drain pipe. This drain doesn't seem to be the greatest. My question is should i just replace the shower drain connector gasket or is it possible to remove the casper drain body from the fiberglass base and install a new drain. the casper unit looks like its glued to the base. what is the best action to take?