might be a longs shot, i've got an intergral resevior 0.75" wilwood master cylinder, installed, with some fluid in it, but its too big, and i need to swap it for a 0.625" one in similar condition.
I might have cut the push rod down too, i can't remember...

anyone interested?

or anyone got a 0.625" integral resevior cylinder they want to move on?

like this one