Does anyone know a source of decently made spirit bubbles? It's for a recently sourced a HR poising tool, with nicely preserved agate jaws. I bought a wee bubble from eBay, but the bottom of it is not flat which is a bit useless. Ideally I'm hoping for something flat I can rest on the jaws.
The original bubble is a curious fish. It's lost all its juice (hopefully not mercury!) possibly by evaporation from a screw plug at the bottom of it.