1989 Toyota pickup lower window channel

My brother just picked up a single cab 89 pickup with a stuck passenger window. When removing the old regulator, we noticed that the lower channel had already been removed from the bottom of the glass. We found the channel and the little rubber gasket that grips the window, but we’re having issues getting it back on. I’ve noticed that when you buy new glass it comes with the channel already in place, which makes me think that we’ll have to replace the glass all together. Does anyone have any experience with this? I realize this is a Tacoma forum and I apologize in advance if I’m in the wrong place.