Hello Nic,
I'm afraid that my immediate reaction to your question is:
So, bang to rights in Reynolds, fig 85, but no evidence that they are Whitefriars - what do you think?
The reasonable answer to your question is:
There is known record for these (and very similar dented and wrythn tumblers) being by a number of STOURBRIDGE makers, and definate proof of them being by John Walsh Walsh, however there is no record of them being made at Whitefriars. It is therefore unlikely that they are by Powell.
The reality is that similar pieces were made by Powell, but the important information is in the detail. In my opion, just as with other pieces that are thought to be by Powell, it is more a question of wishful thinking than them fulfilling the detail of the charcteristics that make them Powell.
By-the-by I have a large crate full of these and the relating stemmed glasses that I would not dream of passing off as by Powell. Any offers?
Nigel