Circuit board underneath the video amplifier tube on these always seem like they're toast. Pay special attention to that area- and install a socket saver to keep the heat from destroying the board any further.
For silicon- there are a handful of recommendations out there but I always use Permatex black RTV silicon from the auto supply- it's "sensor safe" so won't turn acidic later and attack any windings. Hear tell that clear or white "Silicon II" works to- it's designed for bathroom and tiling but I think it only comes in those one-time-use caulking tubes so you'll need a gun. A lag bolt is also recommended to reseal the tube after use.
