Yep, that 1725rpm is a great find. That motor is a workhorse. New, they are the most expensive. Most of the cheaper imports are those 3000rpm screamers that are useless for pipe buffing and so forth.
You Americans get to find the coolest old things! I was lucky once when I got a bandsaw from the 1950ies. Took me two of them to get one complete and it wasn´t cheap too, but hey - you gotta love those old tools....
Woodcraft used to sell spindles and pulleys of various sizes. When I carved a lot of wood I was able to take a 1725 down to 300 with a belt and two pulleys.
I used it for stropping/ sharpening. I didn't want to over heat the edges of the gouges.