hi - the stones/seeds comment refers to the quite common occurrence - in C19 glass - of the presence of some, usually, non-silica contamination from the sand, or the furnace. These are seen mostly as white or black specks (sometimes bigger) and might be undissolved raw materials or impurities from the pots.
Some people also refer to the very small bubbles as seeds.
I agree with your comments about 'doesn't feel like a modern piece' - there is something about table glass approaching 200 years old, that has a certain something. Usually, it's wear, colour, damage, stones/seeds, often a combination of all these features - something that new glass doesn't have.
Have to say that I'm not entirely sure of the meaning of striations... might this be a waviness within the glass?
Ebay attributions/provenance, without qualified evidence of some sort, should be treated with caution - this auction site is littered with descriptions that use word associations to increase value. A vast amount of glass described as Georgian (1714 to 1830) may well not be, although there are some reputable sellers.
There are Waterford catalogues, somewhere, but I've now forgotten who has them.
I would expect to see some damage on a fan escallop border such as yours - unless you've paid a fortune - and wear on the underside of the foot should also be very noticeable, together with some damage to the points of the diamonds.
Probably almost impossible to be certain of an id - and as I say the cutting/design is a not uncommon style and in my opinion too plain for Waterford. Nice piece though, and at least you aren't missing a lid.
Of course, other people might have different ideas - let's hope someone else looks in