Serpentine Antiques has dated this piece to the 1930s.
Makers were Richard Comyns of the very famous William Comyns and Sons, very fine makers.

It seems to have been put away and had little or no use since it was presented as a gift in June of 1930 when it was new. The presentation date is engraved under the base.
Size-3 5/8 inches tall by 2 5/8 inches diameter.
Weight-236 grams.
A lovely mug in wonderful condition. It is unusual to find any of this quality and weight, by such fine makers.
Serpentine Antiques has dated this piece to the 1930s.
Specialising in unique pieces for the discerning individual, selected and prepared with special care..
You can view the stock and full dealer information on the Serpentine Antiques Profile Page