Hi Chris,
You are treading the thin boards pretty deftly there.
[Watch that you don't break a leg!]
----
Perhaps your "Jock" was a John MILLAR ...
... who might then have inspired his younger relation,
William MILLAR (professional alias Stephen BOYD),
born 04-JUL-1931 at Glengormley,
one of nine children of Martha Boyd and
Canadian truck driver James Alexander Millar
... to follow in his acting footsteps in California!
The details of SB's early life and career might provide some hints to guide your research on the earlier period:
http://www.imdb.com/name/nm0000963/biohttp://en.wikipedia.org/wiki/Stephen_Boyd----
A John WHITLEY used to be much in demand for his performances around the Belfast area in the 1940s & 1950s.
However, I think this was because of his singing skills.
So, unlikely to be the 1950s Hollywood actor John WHITELEY!
Wonder if they had any genealogical connection with ...
"Hobart Johnstone WHITLEY was the great developer of the Western United States where he planned and started 140 towns. His final crowning glory was the buying, planning, developing and naming the Southern California city of Hollywood. This started just before the new century 1900. His connection to Scotland was that he was direct heir to the Marques of Annandale."
http://heritage.scotsman.com/mystory/Hollywood-history.2795914.jphttp://www.thefatherofhollywood.com/ ----
Vague recollection ...
A [John?] SHERRARD ran a theatre in Belfast.
[Ref: PRONI card index]
-----
Off to plough the foaming waves some more,
Pip pip!
Capt Jock
