There is an interesting video on the RTÉ Archive, featuring a visit to the CIÉ Liquor Museum in 1962, in the early days of RTÉ Television. The museum was then in the basement of Heuston Station and featured both rare and novelty bottles of alcohol as well as other drinking ephemera
The operator seems very odd. CIÉ, then as now, were the national public transport operator but also had a hotels division - which was reformed as still commonly remembered Great Southern Hotels in 1963, with this being responsible for the museum.
The museum had been moved from Harcourt Street station following its closure in December 1958- it, and the station bar and restaurant, actually outlived railway services there by many months.
Irish Times, October 7 1959
The official re-opening on April 28th, 1961 referenced that it had re-opened earlier in 1961, so it is likely it wasn't closed for very long during the move. This article claims "8,000 tourists" had visited it in Harcourt Street; with the October 1959 article having claimed "16,000 visitors, most of them tourists" by that stage - not the clearest set of figures to try figure out how popular it was!
But for whatever reason, this RTE Archives clip and some other back-references to it are basically the only information online about this Museum. CIÉ continued to own Great Southern until 1990, but it definitely doesn't appear to have lasted that long - so what happened to it?
Well, it seems it moved again. CIÉ also owned canal systems - the Royal since its foundation and the Grand since its nationalisation in 1950 (the nationalisation of both, that is - CIÉ were a private company originally!), until 1986, which may have had some influence on what happened to it next.
The small village of Robertstown in County Kildare is dominated by the Grand Canal, which splits nearby; and its related buildings and facilities, including the large Grand Canal Hotel, which closed as a hotel in 1849 and was then used as an RIC Barracks.
But by the 1960s it was being used as the centrepiece of an annual festival, the "Grand Canal Festa", and it appears housed the Liquor Museum from this time on. Newspaper previews of the Festa each year would mention the Liquor Museum as being provided courtesy of CIÉ.
The Festa was last run in 1975. The Liquor Museum is last referred to in 1978, in a report on a restoration project to the Hotel - which had fallen in to quite some dereliction - with the Museum being mentioned as an exhibition there - but having been closed along with the rest of the building.
This is the last time its mentioned in a currently INA/Irish Times Archive accessible newspaper at least. The Hotel in Robertstown operated as some form of museum and gallery in to the early/mid 00s, and I suspect that the Kildare County Archives may have some more information on what was in it, and what happened to its contents when it closed - if the booze was still there at all! By the time of the 2009 Streetview pass, it was significantly boarded up with the one remaining sign outside showing its use as museum fading away
