Ok, so apparently Western Pump does NOT sell RVT100.
Man, nothing like being told one thing over the phone only to get a blank stare when you make the time to go there in person and then ask for it. .. sheesh.
Anyhow rather than drive all over the place on a wild goose chase for some elusive alleged GE product, I bought some All-Glass-Aquarium silicone from Big Al's, so I'm set for now.
But if anyone ever does find the RVT100 in some mythical store, please post back here and let me know where it be so I might know for some future project. .. Many thanks!