The exhaust fixture in the ceiling has two fans.

Fan 1: between the white bulb and red heat lamp
Model: unknown

Fan 2: the one over the white light
Originally Nutone, probably model c-68626 or c-68627
Possible replacements are:

Brand: Packard Inc
Model: 65106, C-Frame, 115V, 3000RPM, CCW, 5/8" stack, 2 3/8" long shaftBathroom Fan

Brand: Supco
Model: Sm555

Brand: Fasco
Model: k110