Saito used to make one - but I believe, like model jet engines, there were bearing problems at multi-tens-of-thousand revs. Meanwhile, all model turbines (which seem to be single-stage and use an impellor and therefore slurp kinetic energy, rather than blades and gas pressure) are steam-hungry.
I'm not sure why there's been little, if any, interest in Tesla turbines for models. (You get rotation from a steam jet without the need for difficult-to-make balanced turbine blades. The axis of a Tesla turbine would emit low pressure steam/water, and might offer some of the benefits of a condenser without (umm) having a condenser.
All these small-size turbines would need gearing - quite drastic gearing in many cases - to reach normal model propellor revs.
A raft of problems.

I wonder if there's a preference to seeing cylinders and pistons "doing their thing" in the live-steam world, rather than plugging in some covered turbine and getting little more than a rotating shaft and a whine out of it?

Andy