OK, let's see if I got this....
You need a screwdriver to get to the "main", and you need fusepullers.
The feed goes from the meter, to the fuse block, to the contactor, then to the FPE, and out the gnawed hole to get up to the signage. Then there's the "convenience outlet" that looks like it's tapped off of the left fuse. (Guess they're 60's by size, compared to the tc face) Clock is tapped off of the fuse (or line side of contactor)
WOW, that's similar to a mess we found last Monday. Vintage work, many "patches", it's time to "run like heck", or rip it all out & start over.