There are a few models that have the pot motor, but I think there's only one other 15 that has it. 101, 201-2, 1200( a 201-2 with a foot operated presser foot lift in a factory table), 15-91, 15-125(a 15-91 in a new dress) and some 191s. This may not be a complete list. The 15-125 is green so it's obvious. How the machine is powered is what designates the different 15s.
Cari