If you have access to a Mormon Family History Library and can order the films, you could view the films for 1868 containing Skibbereen and take a look.
These films are:
101164 (vol 5 - first quarter), Skibbereen district on pages 667-698
101169 (vol 10 - second quarter), pages 749-784
101174 (vol 15 - third quarter), pages 575-596
101179 (vol 20 - fourth quarter), pages 567-590
Skibbereen has 4 local registration offices: Drimoleague, Skibbereen, Tullagh, and Union Hall, which are all included in those pages.