So I'm trying to find the best replacements for my '78 vintage SR rear derailleur.

So far I've come up with these:
-Bullseye NOS (weird color or expensive. also noisy apparently)
-Suntour sealed (nice but rare and expensive)
-Campy NOS (around $30, prone to cracking)
-Campy repro (apparently well-made, but $40)
-Shimano (poor fit, but that's only what I've heard)

So what is the best option for pulleys under $40, that fit will and won't crack?

Will Campy 9-spd fit? Will any Shimano fit?

Shimano TY series @ ~$8/pr if your going to ride it. They fit just fine. Any Shimano will fit but you dont want a 'floating' upper 'G' pulley.

I've heard good about the metal reproductions made by Some Fab, but couldn't find them just now. Wonder if they stopped making them.

I've always used Bullseye in mine (still have the unused stock pulleys on the basement, not for sale ) and have never had an issue with them regarding noise. Used this same pair of Bullseyes on the previous Nuovo Record as well. That is what I would use...

Here is a pair in red (which are what mine are) for $35 currently
https://www.ebay.com/itm/Bullseye-Der...item20bc8f4712

my apologies if anyone from here is bidding on these.

The Soma "nuovo retro" pullies seem to be fine, and are more like $30/set, I think.

I've heard the Huret ball-bearinged pulleys fit and work well.