you don't mention wear - just possible this might help to assess whether made mid C20 or something nearer to one hundred years or more in age. The fact that these aren't lead glass suggests a lower quality, but I'd still have thought for domestic use rather than a pub, and might be for port.
Whilst we can see most of the detail, clarity and ease of viewing would be helped a lot if the background was less busy. As we're always saying, taking pix of clear glass isn't easy at the best of times, so subjects such as these need plain backgrounds - grey or black perhaps - that will help us to see details to best effect.
You might try the Replacements.com site, but it can take a lot of time wading through copious patterns, and of course these might well not be from the U.K. anyway. That particular site shows glasses designed for a variety of drinks, so that might help narrow down which sort of booze this shape of glass was intended for.
No idea as to exactly when this style of stem started, but would suggest it was most likely Victorian rather than earlier.