I think I have this coin, so I can add pictures (below) as there are none. Mine has large letters like the page above says, but it also says it is 21mm whereas my 1742 coin is 28mm (like the 1742 English 1/2d KM# 579). Is mine a penny instead, so I know which coin to mark in my collection on here? Thanks :)
That's what I thought too - though I see there are some gaps in KM numbers either side of this one. It is KM# 130 and the previous is KM# 125, and the one after is KM# 136. They are, as it happens, both half-penny and both are 21mm. So I now think the page I mentioned is correct with 21mm; and that as an English penny is 28mm, perhaps I have a penny coin that is in one of the gaps i.e. KM# 126 127 128 129 131 132 133 134 135 or others. The only three things I know are correct is it is Irish (from the harp), it is 28mm (I measured it), and the date is 1742 (so is George II, with large letters). Thanks :)
P.S. When in Ireland pages and putting all in KM# order I did see that the three sections are 1928-1971 then Euro 2002+ then these of 997-1928; so in a few year's time perhaps additional Euro coins will be given numbers that mingle with these older ones (the latest Euro coin number KM# 63 and earliest first coin KM# 92). Why would more modern coins be given such numbers I wonder? Putting Irish coins in date order they appear alright though, date-wise.
added the image.- thanks.
however: is the diameter wrong with 21mm? or is your coin another type not listed?
because: it seems your coin has GEORGIUS lettering, not GEORGIVS, and it's 1747