I’ve just discovered that there is an updated edition of the fantastic Dictionary of Ulster Posh Speak by Billy Simpson and Doreen McBride. (In fact, there have been two updated editions – the most recent is A Dictionary of Local Posh Speak.)
Have duly added it to my Amazon wish list. A great-aunt of mine lived in Cherry Velley and spoke classical Ulster Posh Speak, hence the interest. (Her accent was a slightly curious thing to end up with, as she was born in Dublin of English parents, but never mind the technicalities.) My other Cherry Velley-dwelling relatives were migrants from England and never really picked up the lingo.