Replacement Part for Window

I am looking for replacements parts for a single double-hung window. I closed the window the other night and I heard a snap...The window will no longer stay open on its own. After research, I discovered the company I purchased the windows from 13 years ago is out of business and apparently my warranty with them! They manufactured their own windows, but I'm not sure about the parts. I'm hoping you can help me locate the parts to repair this window. This window was installed in 2001, the sticker on the window indicates "Series: Coronado DH AAMA/NWWDA 101/I.S. 2-97, and the plastic casing that houses the coil is stamped 7+7.

Thank you.

I have to replace the lower sash on a double hung window. I can not fins a manufacture's name on the window. The only information I can find is a sticker on the top frame by pulling down the top sash. The sticker info:
NAMI AAMA/NWWDA 101/I.S.2-97 ASTM F 588-97
Code S-019-1
Rating H-R25
series 1000
MST 4060
HUD Accepted Certification Program
2774