Matching window regulators and motors?

I recently acquired a 91 Ford E1 50 van. It seems the window regulators for both the drivers and passenger windows are shot. So far it seems only 92 and forward are available for sale online. Can anyone advise if the part for 91 is still available or maybe what previous year could be changed out to replace the regulator? I would really love to drive this van with the windows down ha ha