I know Cloney Audio in Blackrock stocked some Grados a few years back. Don't know if they still do. I have SR80s and SR325s, I got the 80s in a shop in London and had the 325s shipped by Stoneaudio.co.uk.
Have you tried ebay? Like you I was frustrated that Amazon would not ship Sennheiser Earphones to Ireland so I looked at ebay and bought a set there. They were/are €60 in Tower in Dublin, and I couldn't get them cheaper than €40-45 even in Duty Free. On ebay they cost me €18 delivered and they are perfect.
For some reason I've always felt less secure buying on ebay but every item has arrived safely and as described.
Good luck with your search.