27 4 Caldwell

Thanks for posting. Is the metal channel, not including the attachments at both ends, 28" long? If so, see our S380-28 or S385-28. The only difference between these two balances, as I you might already know, is the bottom nylon shoe depth. See the image below. Based on your pictures, the shoe might be slightly more than 1" deep, in which case the Series 385 is the ticket; but pictures of measuring tape can be deceiving, so please double and triple-check this. You have the right idea. In either case, for a stamp option go with 2740.

Comparison of the S378, S380 and S385 balance shoes.