I know BE&A(and possibly others) sells new lenses. Maybe you can contact Mike and see what he recommends. Mine looks just like yours.
I have some left over foam from the gasket kit I bought from Detroit Muscle Technologies. I suppose one could cut a few doughnuts out of that scrap to use. I guess I don't really know what purpose those gaskets serve. I was just going to leave it like that. I thought maybe it had something to do with how the lenses were held in.