Looking for my dads relatives. Condon from the Mitchelstown area!!!

My dad’s name was Timothy Joseph Condon, I’m hoping to find information about his/ my family. He was born in September 1944 to William Condon and I think his mums name was Sarah. 
He had a sister named Kathleen, who moved to London at some point. She married had 2 children,Fiona, who died at 7yrs old and a son called Paul. He had a brother named Liam, who I think emigrated to America. 
They lived on a farm around Mitchelstown and they were Roman Catholic. 
My dad joined the Royal Marines and spent time in the Falkland Islands in 67/68 where he met and married my mum Susan McKay. They had 2 children myself, Fiona Kathleen Condon(Dilorenzo) and my younger brother David William Condon. As a family we were posted to Hamsworthy,Dorset then to Plymouth Devon. This is when my dad left the Royal Marines. Unfortunately,he died in 2008.

If anyone has any information I would greatly appreciate it. I’m sorry I don’t have any other info. 
 

Look forward to hearing from anyone

Fiona