T-lock balance shoe - Correct part

Hello! I agree, our 15-195 looks like a great match. 

The difference between an open cam and closed cam, or the 15-195 and 15-195B, is that the open cam has a hole straight through to the other side. Your old cam is missing so I can't say for sure which one you need. If you happen to have another window in the house that uses the same hardware then you can use that as a reference.

Also note that when the shoe breaks like this, the balance may not be far behind. It probably still have a couple years of life left in it, ut it is something you want to be mindful of in the future. Sooner or later you will need new balances.