Channel balance for tilt Stanley window

Thanks for posting. It appears you have a Series 795 Channel Balance that uses the 15-195B Open Cam T-Lock Shoe, or a shoe where you can "see through" the back of the cam. The shoe that comes by default with this balance is the 15-195 Closed Cam Shoe. You'll have to buy the 15-195B separately and swap out the shoes. This is a very straightforward process that the video below illustrates. 

Now, as far as the balance itself, you have to choose the proper length and stamp option. Typically, a Series 795 stamped '14' would be 14" long; however, your stamp is a little unusual, since most balances of this type have a stamp that begins with a two digit number and then a letter, whereas yours does not. To be extra safe, please measure the metal channel, not including the shoe. I believe it will either be 14" or maybe 15" long, so you'd need either a S795-14 or S795-15. Finally, you need to choose a stamp option, which indicates the strength of the balance. Again, your stamp is a bit unusual, so what I'd like you to do is obtain the exact weight of the window sash. This can be done using a bathroom scale. Give us that exact weight, and that should narrow down what stamp you might need. Many thanks. 

In that case, we will need to know the exact weight of the sash, as described above. Your stamp indicates a heavier-than average calibration for a 15" channel and there is a good chance this will have to be custom made. Knowing the sash weight will allow us to know for sure.