thanks Anne

That was well spotted finding the similarly cut tumbler in Brooks booklet, and in the absence of anything to the contrary, I think we could go with that date of 1831 - I use his booklet when discussing tumblers but am sure I wouldn't have looked on this occasion.
The foot diameter being wider than the bowl rim, is used often as an indicator of age, but not sure what we should read into this with this glass, but it's a good piece.
Some years back, Barrie Skelcher did a couple of books solely on uranium glass (Schiffer publications) and they're well worth having if that stuff floats your boat. He was a physicist first (and a very clever one), and a collector of uranium glass second, and the fact that his glass research was buried in just these two books, probably meant that his thoughts on other aspects of glass manufacture didn't always get the airing they deserved.
In 'The Big Book of Vaseline Glass' (2002) - and amongst discussions on a variety of glass hallmarks - he goes into some depth as to "When Was It Made", and subjects such as The Gadget, Making the Foot, plus how to separate the several types of feet - hand shaped - blown and molded feet - are examined.
One of the things he dismisses, is Wilkinson's assertion that the gadget goes back as far as c. 1830, and says " ............…. an article made using a gadget would not be earlier than 1870". He does explain in some detail the reasons for this adjustment of the date, but too long to relate here.
I'd forgotten Skelcher's comments re the foot, so will have a look later today to see if his thoughts offer any insight regarding the foot on this piece - it may not of course.
So - do we consider this suggested dated of 1831 qualifies this glass as 'Regency'
