Small iridescent vase with applied handles, ca. 1900

Back to the flea market - this is a sweet little cabinet vase that stands about 3.5" tall. The color comes from what appears to be a blue-green "stain" treatment that has been brushed on to the outside and baked on. Holding it up to the light, you can see the brush marks, and the stain does not wash off, so I assume this was all done at the factory? It has an applied rim with a polished pontil, and a Roman numeral I etched on the bottom. I'm calling it Austrian or German based on similar things I've seen, but the question is by no means settled. Any ideas would be welcomed!