My ones came from around Pomeroy area: Six Mile Cross, Turnabarson and Gortnagarron. There are various spellings of the surname including KILGRIESH and GILGREESH; but in Australia they became GILCHRIST. I vaguely remember my late mother mentioning family in New Zealand but they would have to have been remote as we are slowly accounting for the more immediate ones.
I know there are several GILCHRIST researchers in NZ that I have been intouch with several years ago.
I will keep the information and if I come across anything that I think will help I'll let you know.