I think the tank is okay, I can seen with my magnifying table lamp where the joint melted and while there seemed to be a lot of blobs I don't think the front cap is compromised. These early Empires are built like tanks. Which seeing how the heater blanket measured correctly, that just shows how well they were made.
On top of that, the tank cleaned up very nicely, if I say so myself (and I do)! Even if there is a slight leak at the seam, I think I'll just use the trick I learned here and use some Gorilla Glue gel on it (rather than try and heat it up).