26-3 EH5 CMC 75

That stamp code tells us the strength of the spring inside the balance, but not its identity. To do that we need to see the nylon fittings on either end of the balance. Could you also confirm the length of the metal channel as well? From there, we'll do our best to help. Many thanks. 

This looks like either an S380-27 or S385-27. The only difference between these two balances is the depth, or heel-to-toe measurement, of the bottom nylon shoe, so compare both with your old hardware to see what matches best. You will need a stamp option of 2630.