Just one in the UK and three in Eire. There was a second in the UK, but that's now back on the G register after the owner upgraded to an R66.
I think the only other non-G reg R44s in the UK are two registered in the Netherlands.
The maintenance aspect of R44s (in terms of engineers with FAA tickets) may have been expanded of late with all the N-reg R66s around. I realise they are different types, but it may have opened up new opportunities for N-reg R44s, that's all I mean.