Wow, what a speedy answer!
I've had a good look at the original map and on this smaller one, right on the bottom edge, is a bulge that is labelled Glassworks on the bigger one - by my reckoning this is the Ringsend Bottle Works, on Fitzwilliam Quay.
On Charlotte Quay there should be the Irish Glass Bottle Works at this date? No sign of it, I am puzzled. I have no other address in this era.
I also had a look at North Lotts (says just Lotts here) but it is jam full of buildings so I can't see the Dublin Bottle Works.
I have been doing a lot of reserach and I reckon my ggfather worked at the RBW, then the IGBW, then ran the Hibernian Bottle works which opened later. He went bankrupt.
Many thanks, Alison