Help Identifying Hardware

Thanks for your photos. Based on what I see here, you have either our Series 351 or Series 390 depending on the depth of the bottom shoe. That's the only difference between them. I recommend measuring your shoe and referring to our dimensions to confirm the best match. 

For reference, the Series 351 has a 1" deep shoe while the Series 390 has a 1-1/8" deep shoe. You can see examples of this on their respective store pages, linked in this response.

It also looks like your balances have different stamp options, which is no good. If the windows are identical then the stamps really should be, as well, but that's something you have to confirm before you buy anything. To summarize, the stamp represents a specific spring calibration for that particular size balance. If the same window uses different stamped balances, it won't work properly, since it would have uneven tension.

We have a chart on each balance store page on our site that tells you precisely how much weight each stamp carries. You need to weigh your sash on a bathroom scale and refer to that chart to determine the best option. I recommend you do this for each window you want to repair. I know that's a lot of work, but better safe than sorry.