Should add that the McDonagh's building on Merchant's Road has a wonderfully restored original interior as well (apart from a nasty laminate timber floor that's pretty shoddy looking. The previous tenants were a furniture store but they painted the exterior a really unfortnuate peach colour. It was originally white and looked great. It's currently lying empty - used as a hugely impressive box office for Galway Arts Festival last year with a great display of photos from festivals gone by. I believe, and I may be wrong, that it's now owned by developer extraordinaire Gerry Barrett (aka Edward) so I'd have high hopes that whatever it's future use the fabric and character of the building will be well respected. It'd make a great gallery space or i've even imagined it as a really chilled bar/restaurant/venue. In the daytime the quality of light inside is wonderful.
Theres a couple more buildings not mentioned yet that I'd see as being in the "Deco" style - the old Silke's warehouse near Dominic St. is a lovely building and could really do with some TLC. Seapoint in Salthill also has echoes of the style and by all accounts has a wonderful old dance hall on the upper floors - I havent seen it myself but Id assume it'd have a fairly streamlined deco type interior. It's yet another building in Galway that's underutilized though. Id love to see big gigs and events back there but apparently the lack of wheelchair accessibility has the place lying empty.