Deve, you asked about sealers. Have you ever used Right-Stuff sealer? You can use it on very damaged sheet metal, like your pan and still get a good seal. Be warned, you will probably bend the pan getting back off if needed. This stuff will seal anything, with or without gaskets. I like for jobs I don't expect to see again.
One thing about silicone sealers, they will not stick to oily surfaces, even very little oil. Use a brake cleaner spray or lacquer thinner to really dry out both surfaces. Plus, do not let the silicone dry or start to harden up before tightening the bolts. If you want the gasket to stay in place, seal one side and bolt the pan down to flatten the sealer and gasket, once it drys, pull the pan and do the other side. You can get high spots in the drying sealer if you wait to long to assemble.
