If you want to keep using it, dont' think I'd recommend trying to add sealant. The ALL leak; that's what the drain tubes are for. Check that first. I tried to replace the seal on my '93 (different from yours) and the bakelite surrounding the glass just disinegrated. It lasted 2 days. Manged to find the whole insert (new everything) and dropped it in (four bolts, as I remember). But that was an expensive option (but then, it worked). If you don't want to use it, you can likely seal it with silicone.