Caldwell 27" channel balance replacement
I am a little confused from the start. Your title states that this balance is 27", however, when I look at the ruler in your first photos, it shows the metal length measurement of your balance is 21". And when I also see your stamping of "20 ", that also tells me that the metal length measurement of your balance should measure 21" in length. Could you please clarify the length that you need? In the meantime, have a look at our Series 380 channel balance. This comes with a 19-005 balance top and 15-005 bottom balance shoe. You want to confirm the 'depth' of your bottom balance shoe matches up with ours.
The bottom shoe does appear to match the 15-005, but the top is not as pointed on the end. I don't know if that makes a difference or not.
No, the Series 380 should work. As long as the 'depth' measurement of the bottom balance shoe matches up to yours, like you have already mentioned, then you should be good to go.