Re: Filling cracks in wavy glass instead of replacing?
I glued a broken pane of etched stained glass back together with epoxy, left a good uniform bead of it on the glass to aid in holding it together, and colored the cement with a red sharpie to get rid of the clear seam line (it was red flashed glass) and it has done okay for 3 years. On clear glass the epoxy is going to yellow noticeably. A thick superglue could also work, may not yellow as badly.
It used to be commonplace (about 300 years ago) to repair broken panes with lead came, as in leaded glass. Many Victorian windows (the crazy-quilt style) emulate this and take it to an extreme.
Remove not the ancient landmark, which your fathers have set.