If it is what I am thinking (and the slide printer I have), you can get Fuji FP-100c. It will fit, but is 100 speed. I think the 669 might have been ISO 80, so it isn't really a problem.
This is not the integral film most people think of, but a "peel-apart" film (both the Polaroid and Fuji).

This is the printer I am thinking it is: