Fatal to generalize, but.....the older a glass is then I get the impression (provided it is genuine) that it is easier to date or attribute to some style or other. Unfortunately, some characteristics i.e. the ground/polished pontil, have been universal for so long that they don't really help - they've been around from 1780 ish to the present time almost. Likewise cut flutes and bucket bowl shapes seem have been design features for a very long time - particularly the flutes which appear on all sorts of glasses including tumblers etc. However, some aspects, like colour can be very helpful, together with the striations and blips etc. on the bowl, and if indeed it has a gadget mark then date wise it should be somewhere between c.1870 and c.1900 ish - certainly a little earlier than I had originally thought. However, am I correct in thinking that a glass shows either a gadget mark (on more utilitarian pieces)
OR a ground/polished pontil mark, but cannot show both?? Have you looked with the torch to see if there is any 'manganese green', and would be interesting to know if your glass 'rings', and I believe the description of your example places it within the group called 'rudimentary' stemmed glasses.
Had your glass a simple bladed knop, then I would have said early C19 (almost without hesitation

) - there are literally, shed loads of C19 rummers with bladed knops or annular ring knops, but not cut ones. Can't think why I should have made reference to Reynolds, total rubbish.
So, could be last quarter of the C19 - but that cut knop remains to confuse - and the colourless glass seems to indicate no great age.