Do you have this balance shoe?

Thanks for posting! This shoe resembles our 15-014, however we do not recommend replacing the shoe by itself as you would have to reset spring tension, and that can often be dangerous. I think you should consider replacing the whole balance. See our S751-28, which I think closely resembles yours.

Yes, I think that's a good way to go. Usually a stamp of 27HD indicates a balance length of 28". I know that can be confusing, but it's just the way these balances are.