sincere thanks to those people who replied and offered advice regarding the Gulliver volumes - although it looks like I shall have to go on wishing for them at the moment (I've given up paying mortgages - or at least thought I had

).
I have five of these tumblers (4" in height), in green, all of which are unmarked, completely - and all of which have a large ground/polished pontil, which seems to have been typical of Stuart. Do people think there is any way of knowing whether the flat bottomed examples are earlier or later than those with a pontil depression - or might they have co-existed? From what I can see, most pieces carrying known early Stuart marks seem to show pontil depressions (the remainder being star cut bases).
It may be worth commenting - should there be the remotest chance of confusion for the less knowledgable like myself - that on rare occasions it is possible to see an upper case S which has nothing to do with Stonier/Stuart.
Just rarely, the 'S' (for Stourbridge), which forms the central part of the circular backstamp for Webb Corbett - remains more visible than the remainder of the mark - giving the impression that the piece carries just the letter 'S'. However, a careful look should reveal at least part of the words of the rest of the mark (which I understand was used during the late 1940's).
My large cut bowl with an S must have been a b......... to have sneaked into someone's pocket, as they departed the vessel after their cruise