The percolating sounds are normal.  My '57 GE combination makes perking -- almost popping -- sounds in the freezer when it's cycling.  Doesn't your '57 do likewise?  Is the sound your '53 is making different?  Even if it is, I'm betting it's normal. 

Are you referring to the drain pan that catches the defrost water?  I'd say any sort of caulking or silicone sealer would work.

The back of your '53 is where the condenser coils are located.  On your '57, these coils are tucked underneath the fridge behind the front grille, and there's a fan that draws air across them for cooling purposes and blows it out the left front of the grille over the drain pan to help that water evaporate.  This is called a "forced draft" system and allows for this type of fridge to be built into a snug cabinet surround if desired.

Your '53 has a passive system for cooling the condenser coils, which is very common even on modern day refrigerators that have the coils on the back, and there is no condenser fan involved (which is why your '53 has a solid toe kick plate at the bottom up front instead of a grille).  This passive system requires extra room behind (and to a certain degree, above) the refrigerator, so your '53 is going to stick out more than your '57 currently does.

The noise is probably normal.

 I used to fix cracked drain pans with gray tape on the outside, caulk, or silicone on the inside.

My '57 varies in noise level, but it's generally very quiet.  It seems to run even quieter when ambient temperatures are warm, like on hot days (we have no A/C).  The perking sounds it makes are only heard inside the freezer while its cycling.  They aren't audible with the freezer door closed.

Regardless, your '53 might be making noise as a result of having been moved and defrosted.  It will likely run quietly -- even more quiet than your '57 because there's no fan running -- after it has been operating for a while.

Keep us posted!

The compressor was likely painted black to begin with.  The crust could just be deteriorated paint.

The insulation probably served a purpose, so I'd put it back.  As long as the fridge is cooling and not making any strange noises, let it run and see how it does.  Put a glass of water in the fridge and stick a thermometer in it.  Check the temp after 24 hours.

If look are not as important as function, that spray on stuff that seals leaks actually works. I saw a couple reviews and it says it's good stuff. Flex Seal.

jamman_98

joe

That compressor looks pretty normal, for 60+ years old.

Where the drain pan sits should be warm. They put the drain pan there to help evaporate any water that ends up there.

Just noticed, your 'fridge is almost the twin to Ricks, except they're hinged on different sides.