A glass shop can help. Some have templates dating to the thirties, course, yours may be different. You need to provide a template, an accurate measurement of the channel width and the channel in the lifter. The glass shop can cut the glass, provide correct seating tape for the lifter, and correct (the proper name escapes me) felts for the channels. All with one easy stop.
Others may think of something else the shop will need, but it should be easy assuming it's flat glass.