Bought wrong 1 1/4" T-Lock balance shoes open cam.

Hello! We sell the 15-236 T lock shoe, which has the same deep indent on the stem as your original. The downside is that we currently can only supply this with a closed cam, not an open cam like your original. Look it over and see if you still want to give it a shot.

There is unfortunately not an easy way to gauge that, no. In all honestly your pivot bar may be a little too long for the 15-236, but this is one of those things that you won't know for sure unless you try it. In a worst case scenario, adjustment of the position of the pivot bar on the sash may be necessary, or even grinding down the tip that fits into the cam. 

I am sorry that I can't offer you an easier solution. The only other option we have is to replace the entire balance with our Series 795 and use the 15-195B that you already purchased on that, since they are compatible.