Front sliding window

[d. winchtester]

Would anyone know where I could find the sliding portion of the drivers
side front window. The small one next to the front seat. Does any one
know if this piece can be installed without removing the window frame
and dismantling it. I have had a plastic window for about 15 years
because we could not find a replacement back then. The first one just
exploded while siting in a parking lot.

Thanks Dan W
78 Royal