the Ulster American Folk Park near Omagh also has emigration records so give them a bell to see if they will be helpful
and the Public Record Office in Belfast
There is a great bluegrass/old timey festival at Ulster American folk park this weekend. You'll miss this annual event, but maybe the organiser of it can help you with musical queries?

I think the Ballycastle folk club meets on Monday nights

In Derry city there is usually a session at Sandinos, near the bus station, Sundays from about 4.30/5 pm. On the last Sunday of the month there is a folk club (singers circle, instruments welcome)at the Verbal Arts Centre, opposite the courthouse, from 8/8.30 until 11/11.30 pm

also check with the Harbour Museum in Derry re your research