Top Sash Guide
The top flat plastic part is 3/4" wide, overall height is 1 5/16, and the lower portion of the guide is about 1/2". Window is 20 years old and made by Pacific Window.
For the Top Sash Guide, you may need either our 18-108 or 18-196. Compare both with your old guide to see if either matches up. For the balances, I am afraid that stamp code doesn't tell us its identity, just its spring strength. Please remove the balance from the window and show us the nylon fittings on either end. See the video below for details.
Sorry to hear the 18-108 didn't work for you. Yes, view our Return Policy here. As far as the correct Top Sash Guide, if the dimensions are exactly right, then yes, we think the 18-036 is the closest match we have. You would have to drill a hole in the top portion to get it to work for your window. Let me know what you think.