Taken me a while but I have found an example from the Percival Vickers "Milan" set. This service consisted of at least 25 pieces, available in frosted and plain. It was never registered but from looking in the P&V pressed glass catalogue I would say it dates to about 1867-1868. This piece is the smallest of the available comports at 6 inches - they were available up to 10 inches. The size measurement they used is the diameter of the top plate rather than the height of the comport.
What's interesting about this one is that it shows the height of 1860s Manchester frosting mania, where they just frosted the whole thing without any pattern. Molineaux Webb did a similar set and registered theirs in 1868. I am showing photos of the Milan piece and a MolWebb celery for comparison and you can see that apart from the design of the edges, the bodies were patternless whole frosted.