Service entrance sealing

[Fritz57]

Ida has made me aware, unfortunately, that the service entrance conduit to the house, is leaky.
I have one breaker that has corroded to the point of gone bad.
Others have some minor rust at the screw, but appear to be good.
There is a Master breaker, so that's good.

The box appear to have a little moisture/condensation inside, but not a puddle.

The pipe above is gas.
The shingles are old school asbestos.
What is best to reseal this entrance?
I assume chip off the old as best I can.
Should I use duct seal or GE outdoor Silicon caulk or ...?
thanks,
Fritz

 

[Fitter30]

Polyurethane caulk from the outside then expanding foam inside for insulation.