26" Channel replacement

I'm afraid that I don't recognize this balance based on these photos. They're just a little too unclear. Would it be possible to see a clearer photo of the top fitting. I also note that your balance is missing the bottom fitting. Is that by design, or has it broken off? If it broke off, can we see it? Lastly, I'd like a photo of the balance on the opposite side of the window, just in case. 

I think I have an idea of what you may have but seeing both balances together will be necessary to confirm. If I'm right then they will be different; I believe this is one of the few balances ever made where that's the case.