Once you have the block out (you did take pictures or do a drawing??), you will need 3 things from the Dollar store. Plastic long sealing tub, stiff tooth brush and big bottle of lemon juice. You will need some salt too but there should be some in the cabinet.
Place fuse block in tray and fill 2/3 with lemon juice. Put lid on and shake up making sure everything gets coated. Wait 5 minutes and turn block over for another 5 min. Take stiff toothbrush and get after it. For the dark spots, put some salt on brush and scrub. Rinse clean. Your should be good for another lifetime.

I use vinegar but same idea. I think it works best to buy a second fuse block, clean it and transfer one wire at a time. Then clean your old one and sell it or put away for the next 40 years.

Spare block is handy.

Done this many times.
I use a AA electric tooth brush, the type with the replaceable head. The wife replaces the tooth bushes every few years and there's usually nothing wrong with them, so they get re-purposed.
I just saw she bought a large brush head kit from Costco...so this reminds me to go steal a couple

What should you rinse it clean with, is water ok?
Is it bad to soak it in the lemon juice overnight or not necessary?

Thanks,

About 5 min a side is good. Should clean up really quick. Rinse in plain old water. You can even get some Brasso and polish the terminals if you want.

Excellent post Mark.

I like to add a little tequila to my lemon juice then my fuse block looks much better

Every time I put tequila in with my lemon juice my car stumbles and won't drive straight for a few hours. Maybe I'm putting in too much??

She never notices it tastes like lemon?

Fuses came in today so I loaded it for 1974 -76.

Stock in used, were about give aways, just went up. When I was tearing apart way cheap beaters, now 'B' level projects, I don't think I ever pulled one.

Good write up!