I'd assumed this was British, but in view of the unusual format of marking I'm now not sure, and wonder if this piece might be either from the States, or modern.
The wording on the underside says.....'IMPERIAL 1/2 PINT', and although in relief as you'd expect, as can be seen, the wording is in mirror image i.e. running from right to left.
Height is something like 4.25"/108mm, and the colour and flow of glass streaks seems o.k., although I don't have any other pieces with which to make a comparison. Thanks for looking
