I made the mistake of looking around eBay last week, and put in a silly bid for a W T Avery Balance which took my fancy. It turned up today.

It's a bit bigger than I had imagined, but is a thing of beauty complete with knife edge bearings. shining in gold lacquer on solid Brass

I'm going to make it a home on the shelf, but I'll need to raise the shelf above it by a couple of inches to make it fit. You think you've got your bench all tidy and then eBay sends more toys - Still, I'm sure it will come in handy.