All answers are surnames popular in N. Ireland
No. 1. Coins and notes by the sound (6)
No. 4. Second in line is in hysterics (11)
No. 7. 19km south of a Tyrone border town (8)
No. 9. Orient coppice (8)
No. 10. Remove a vowel from each day(4)
No. 16. Originally called- star for earth to orbit(6)
No. 18 can be Indian or Chinese (6)