Balance ID

I have a window balance stamped 33G BSI TK. Looks like rust at the bottom and plastic pieces broke off so I have no way of reproducing what those parts should look like. The builder tells me that the windows were MW industries Patriot series. The "DO NOT REMOVE" label itself shows 84 lmbr and store number plus a bunch of other letters and numbers. It looks like there are two springs, an outside and an inside. Anything you can do for me? Thank you!