Help with a pivot arm
The model 26-336 does not fit, I already ordered 2 and tried them.
I'm sorry to say that the 26-336 is currently the only pivot bar on the market that could potentially work for this application as-is. Simonton discontinued your original style and replaced it with the 26-336. As a result, your original part is no longer made. I don't know any store that may still carry it.
The 26-336 may still work for you, but it would take some handiwork. Namely you would need to grind down the "collar" on the front tip so that it's a little more flat. I've found this to be a reasonable solution in most cases, but it's not ideal. It's also important to note that any product altered in this way can no loner be returned for a refund.
I'm sorry that we can't offer you an easier solution. Your old part just isn't made anymore.