Welcome also. I think I've had 2 or 3 237s, but not with a covered motor like that. I would be curious to see the back of the machine with the back cover off; would the internal workings be exposed?
I think of an internal motor, for Singers anyway, as a shaft drive to a geared handwheel as in a 301, 401, and Rocketeers. I guess I need to rethink this.