Mr. Jake Johnson posted a Pic of a roller stand he was using to tune locos for a large On3 layout build. I asked where he got them and the response was...Micromark!
So I heated up the computer and found that Micromark makes the same piece for HO. These are designed to fit over existing track to create a standing test track. So I ordered a set of four--I recall they night have been $40.
These appear to be stainless rollers set in aluminum angle and held apart with a plastic/vinyl piece. Hmm. Recall that HO standard gauge is a scoonch wider than Sn3. C&S crews are measuring a roller assembly to create styrene fillers to adjust the gauge to Sn3. The screws through the plastic extend through the angle to create gauge studs to hold the assembly in place on the track.
Another problem solved. Almost.
Keith Hayes
Leadville in Sn3