CAUT

I replaced a set recently on a 1980s SD- 10 with a smaller set of wheels- the pedals were really high with the 3 1/2 in casters. I think the 2 1/2 casters came off a European grand about the same vintage- brought the pedals down a lot, so you might want to see what you can get. I think the Brass ferrules for both the large and smaller casters is about 1 1/8" shaft, screw holes were close enough for making the change.