Jug in V&A identified as Thomas Webb with a diamond registration mark for the reeded scroll feet design and handle. A good example online to show the difference between these feet and Greg's bowl:
https://collections.vam.ac.uk/item/O1192596/decanter-jug-and-ofallon-james/Greg's bowl feet here:
https://www.glassmessages.com/index.php?action=dlattach;topic=67303.0;attach=219392;imageI couldn't see this decanter example in 'British Glass 1800-1914,
Hajdamach' . Neither is the diamond reg mark shown on page 448 under heading ' Thomas Webb marks'.
Also the designer information - I have a query over the dates:
V&A says:
'
Decanter jug and ball stopper, engraved glass, set on four scrolled shell feet and with a scrolled shell handle, with a representation of the Punishment of Cupid on the ovoid body, probably designed by James O'Fallon, made by Thomas Webb & Sons, Amblecote, ca. 1870[/b].'
and
'Diamond registration mark for 19 October 1867. (Registration mark on the underside of the base for the shell feet and handle.)'Hajdamach in British Glass 1800-1914 page 428 says:
'[
]James O'Fallon, an expert in the carving of fruit and flowers, was Art Director at Dennis Glass Works for many years. He left the company in the early 1920s after more than forty years' service.[/b]
I suppose 'more than 40 years service is stretchable in terms of dates but him leaving in the early 1920s and going back over 40 years service, say 45 years ? could take it back to 1878. A little later than the diamond reg mark and the c. date of the jug of 1870.
He was there in 1878 as The Pottery and Glass Trades Journal said he was complimented by the Prince of Wales on a large jug with a masked engraved handle:
see page 150
https://www.google.co.uk/books/edition/The_Pottery_Glass_Trades_Journal/hyUGAAAAQAAJ?hl=en&gbpv=1&dq=thomas+webb+registration+mark&pg=PA150&printsec=frontcover