My grandfather Robert McGarr is probably one of the siblings you mention in your message. He is from Wallsend and now lives in Killingworth (incase he is here is some data for your family tree).
Robert (Bob) had three sons - Micheal (youngest), David and Robert(eldest)with Anne McGarr (my Nana) who passed away last year.
Robert McGarr (my dad) had two sons and a daughter - myself (24yrs old), Philip (23 yrs old) and Helen (20 yrs old). Myself and Helen now live in Leeds and Philip lives in Nottingham. Robert lives at our family home in Whitley Bay.
David McGarr has a son Paul and and two Daughters Nicola and Kelly. Nicola has three children - two daughters (Racheal & Emily) and a son (Joseph). Paul has a baby on the way with wife Sarah.
Micheal has no children (or none that anyone knows of).
Please give me an email Richard.McGarr@jacobs.com if you have any questions or if you want me to find anything out for you. I would be interested in seeing the family tree (if its the right one).