31 3 ev cmc 7

Thanks for posting. This appears to be either an S380-32 or S385-32 Channel Balance. The only difference between these two balances is the 'depth' of the bottom nylon shoe, or the measurement from heel-to-toe. See the diagram below for reference. Compare both with your old hardware to see what matches best. In either case for a stamp option choose 3130.

Comparison of the S378, S380 and S385 balance shoes.