broken sash

I see that you mentioned our Series 380 channel balance as being a match for your balance. I do see some similarities between the two. You also mentioned the balance length to be 23". If that is the case, then you would go with the S380-23 channel balance as a replacement. To choose the option, you would need to look over your channel balance to see if there is any stamping or marking on it. If so, please provide us with that number. Since you do not have a scale to weigh your sash, you will need to provide us with the visible glass size measurement you see in the sash, as well as the width by height. Lastly, let us know whether or not this window has insulated glass.  

That's a very large sash. I've estimated the sash as 30 pounds, which would mean the 2260 option is the best choice. However, this is just an educated guess. If you have no stamp on the original balance, the only way to be 100% sure is to weigh the sash on a scale.