WIndoe parts
Looks like you need a new spiral balance. They don't make spiral balances like this with a 1/2" diameter tube, though. You should triple check that. The only two options are 9/16" and 3/8". Make sure to only measure the outer tube, not the interior spring.
If your outer tube is 3/8" then I recommend the Series 900. If it's 9/16", you can use our Series 600.
Additionally, your pivot shoe appears to match our 15-134. This is commonly used with the skinnier Series 900, so keep that in mind. Just review the dimensions below to confirm they match.
We do not sell that white cap, unfortunately, though both balances I recommended come in the requested sizes. You can see a full list of sizes available for both Series by clicking on the links I provided above.
As for the pivot bar, we don't sell this exact type. However the 15-134 is specifically designed to work with the 26-297. I know for a fact that this will work with the new shoe, but I don't know how well it will fit in your window. Review its dimensions and see what you think.
