Hi Thelma,
Thanks for the link. It proves to be a great source of missing information regarding the Montgomery family in Arran and will keep me busy for days to come.
Some details differ from what I received from the Arran Heritage Museum regards John McIntyre Montgomery (1891).
According to them; the parents were John Montgomery and Catherine McIntyre not James Cook Montgomery and Violet McIntyre.
John and James were brothers. Catherine and Violet were sister. Brothers married sister. Both couples each had a son they named John McIntyre Montgomery

John and Catherine's son was born in 1891.
Whilst James and Violet's son wasn't born until 1908 and in 1929 was recorded as living at 11 Lansdown Crescent, Glasgow, Lanarkshire, Scotland.
The marriage to Mary Christian Fullarton is correct though and would have been the Mary Montgomery (nee: Fullarton) that arrived at Ellis Island in 1922. They married in 1921 and she died in 1923. I'm guessing he married Joan Thedans when he was already living in the U.S.A. As in the 1930 US Oakland Census it states that she didn't immigrated until 1924.
I think having these two John McIntyre Montgomery's on the same generation line causes confusion So either the Arran Heritage Museum has incorrect records or the website compiler has. Only death records are going to clear up which is correct.
Oh

by the way what is RAOGK and SSN papers (sorry new to genealogy research

)
Once again thank you for all your help Thelma it is very, very much appreciated

.
Stewart