Traco Window - Won't stay open

We have some windows that made Traco and they will no longer stay open. They were installed back in the mid to late 90's.

From what we gleaned from your site, the spring broke on both side of the sash.

We do not have the window information any longer, but we've taken some photos to provided some idea on what may be be need.

Spring is 35" at 7# (see photo).

The jam track measures (as best able to measure) 1-3/8" wide x 9/16" deep.

The coil pivot shoe measures 2-1/4" tall