Frank.... I'm off to look up H Wilkinson from Amblecote now.
With regards Gray Stan, I don't think it was classed as a potential non-runner on the basis of the pontil mark alone. So far on Gray Stan I think the no's have been:
a) Nigel has mentioned that the pontil mark doesn't look right, I have only two pieces of Gray Stan and they both have immaculately snapped off pontil marks where a vertical line can be seen, this decanter has a very neat snapped of circle.
b) I have a clear footed Gray Stan vase here with amber trails that appears in the same catalogue advertisement as what appear to be two pieces from their Flint Dot Enamel range. I was therefore thinking there might be more similarities between the pieces given they appear to have been produced at a similar time as they appear in the same advert. Apart from the pontil mark being different, the clear glass is different in that in the vase it has some tiny bubbles in but nowhere near the amount of minute bubbles that are in the clear of the decanter and the amber trails are a different colour in that they are yellowy amber and don't glow under blacklight whereas the decanter dots and neck colour is definitely orange and they look neon under blacklight. However both the orange on the decanter and the amber trails on the footed vase are full of tiny bubbles now I examine them both more minutely. (Source -Charles Hajdamach 20th Century British Glass book page 93 plate 178- my amber trailed vase is pictured 3rd from left top row, and stands next to what seems to be a Flint Dotted Enamel lidded pot 2nd from left top row and on the bottom of that plate bottom row 2nd from right is what appears to be a perfume bottle Flint Dotted Enamel).
c) I did raise the possibility of Gray Stan with the V& A and said it was thought to possibly be a non runner at this stage and the thoughts from the V&A was that Gray Stan usually worked with high lead-glass and that the decanter didn't appear to be this - sorry I really can't tell whether it is or isn't but I assume not because my footed vase and my candlestick ring like a bell whereas the decanter has a dull 'thud'. But maybe that is also a function of the shape of the piece? I don't know enough about glass to know that, however they just don't feel to be the same kind of glass though.
My thoughts are that despite all these no's, I still look at it and the work gone into it and feel it sits well enough to have been a piece of Gray Stan or similar. It feels too much work has gone into it for it to be a 'workaday' piece. But it doesn't feel as 'refined' as my two GS pieces somehow.
Lastly, I found a vase on a site that has a dotted enamel effect and that was attributed as possibly Orrefors or Stevens and Williams??? did both those companies deploy this dotted enamel technique? I've not been able to find any evidence to support this, but then I have so little resources bookwise, in this area.
sorry for the lengthy reply.