Updated 4 March 2000
The Ordnance Survey of Ireland is in the process of changing the scale of the maps they produce to a pure metric system. A map that has a cross through it is no longer being printed but there is still an existing stock. As a very current example the 6" series which are to a scale of 1:10,500 have largely been replaced by the 1:10,000. There are still an available stock of he six inch series for some places but if you order a six inch you will be supplied with a map to the new scale.
The city maps for Cork and Dublin have long been metrified and are produced to the scales of 1:15,000 and 1:20,000 respectively (4.224" to 1 mile and 3.17" to 1 Mile). In the process the OS started with the 25" series and are working upwards.
To all map seekers the following are the sites for maps of Ireland
Ordnance Survey for the Republic of Ireland
Ordnance Survey for the North of Ireland
History of Ireland plus Map of Ireland
Historical Maps of the North of Ireland
Historical Maps of the Republic linking land ownership from land Valuation data to the corresponding maps including Griffith's Valuation
Irish National Archive including a lookup of Deportation orders