A friend dropped these off the other day:
Missing 1/4"-1/2", 3/4". Duplicate 1"
I cleaned them up, but they appear to have been left sitting as pictured (maybe not in order) in shallow water for a looong time, so some are badly pitted on the reverse. 5/8" is so badly pitted it would be unpleasant to use.
Numbering on the raised panel at the open end is C-**, with the 1" being C-30 and incrementing down by two--were there 1/32" increments in between? Raised letters just below the open end are an alphabet soup of two-letter combos.
Reverse sides bear
FORGED ALLOY IN USA and pitting

It would be fun to complete this set, but I don't really much use SAE sizes any more, except around the shop and we have tools for that.