rubber casters for Steinway

[Fred Sturm]

Does anyone have a source for double rubber caster that will fit into
sockets on a large Steinway grand? To clarify, the modern Steinway
casters for D and B (and maybe other models as well - I haven't checked)
have rather thick and short stems compared to those readily available.
And the sockets are recessed fairly deeply into the wood. Hence,
adapting readily available double rubbers is a big can of worms, and
probably not a good idea.
	Why do I want such a thing? For your amusement and edification (of the
"Now I've heard everything" variety), there is a pretty fancy music
store here (not selling pianos) that has a small recital hall attached.
The stage is maple, finished natural. Brass casters cause dents. Hence,
the owner has the Steinway B sitting on 5 - 6 in caster cups, and when
the piano needs to be moved, has three or four employees more or less
lift and drag the piano, dragging the caster cups along. This has been
going on for a few years. Apparently they are allergic to spider dollies
for aesthetic reasons. I am not their regular tech, but occasionally
tune there for someone who is renting the space. Each time I have
admonished them that they are maybe, just maybe looking for trouble. So
finally the owner thought double rubbers might be okay.
	If I can't find such a thing, maybe I can sell him on those round
cradle affairs for individual legs with outlying rubber casters.
Regards,
Fred Sturm
University of New Mexico