20 c spring balance , cam show and metal cam catch

The cam catch you're looking for is called a pivot bar. Yours in particular looks very similar to our 26-360, but yours seems to have more installation holes than we do. You definitely don't need all of them to match up, so as long as one or two align with the holes on our product then you should be able to use it with no problem.

As for the balance, you have our Series 795 channel balance. Just note that the Series 795 comes with the 15-195 T-lock shoe by default. Your original shoe looks closer to our 15-195B, though, which has an open cam. With that in mind you'll need to purchase our Series 795 and 15-195B shoe separately, then swap the shoes out when you get them. The video below will explain how.