Although there are many similarities, and the needle does face flat left and threads right to left on the 15-91 as it does on the 15-88, the 15-91 is ELECTRIC. And I made a mistake in my earlier answer about identifying this machine through Sandman Collectibles. When you put all of the factors in it identifies it as a 15-96. Go to Sandman Collectibles and try to identify you machine based on your machines parts and structure. See what happens. You can pm me if you have further questions.
Originally Posted by
mom-6
So what is the difference between the 88 and the 91?