"Leon" wrote in message
I was entertaining the feasibility of having casters screw down through
the
middle of each of 4 legs. That however would involve long chains to keep
every thing synchronized or jacking each one down one by one like you have

For a workbench, can I assume you've seen Norm's solution to wheels on a
bench? All he does is lift one end a few inches, kick out the wheel supports
and they drop in place to make his bench mobile.