midlife
Guru
Any 3/32" derailleur chain will do.
Just a thought but if it is older freewheel with plain sprocket teeth with no cutaways or ramps (Regina, Atom, Cyclo etc), you'd probably be better with a cheap basic chain with protruding rivets as the rivets catch the sprockets to change to the next sprocket up. That's how it was supposed to work back in the day. I use ETC, they're cheap enough from Ebay.
I'm sure the KMC Z33 has an old fashioned profile .....
Shaun