Often Thoms Directories only gives the main business in a building, but you could get lucky.
My earliest Thoms is 1922
Ormond Quay Lower
25-27 .. Daniel Egan - art dealer etc
27 .. Michael Clerkin - tobacconist
Ormond Quay Upper
27 .. J & P McGrath .. wine & spirit merchants
edit: looks as if it's Upper .. Shannon and Warren still on the Quay in 1922
regards eadaoin