Mark,
I mentioned the two references above. Those would prove to be the most useful of the several other sources that I am aware of. However, if you are on a quest to gather more information, here is what I have collected over the years. There is probably not much more in any of these than what the two previous references listed above as many have the same photos and comments, but you might find some different color schemes and a few more photos not provided by these first two.
In no particular order:
Aeroplane Magazine from the UK, May 2006. This is from their "Data Base" series. 18 pages. Photos, drawings, small 3-view, interesting reading.
FlyPast magazine from the UK, October 2008. This is from their "In Focus" series. 20 pages. Photos, some color profiles, interesting reading.
Scale Aviation Modeller magazine from the UK, February 1997. Several photos, color cockpit details, 3 pages of color profiles, really good 3-view drawings.
Planes magazine from the UK, October 1984. Really good 3-view drawings on four pages, showing coloring and markings detail.
Westland Whirlwind Described by Bruce Robertson. Published by Kookaburra Technical Publications, Australia, 1970. 26 page booklet with photos, history, cockpit detail photos, good 3-views taken from Westland drawings showing some construction detail, one page of color profiles.
Camouflage & Markings - RAF Fighter Command 1936-1945, book by Goulding and Jones, published in the UK, 1971. Has a 12 page chapter on the Whirlwind, gives a short history. some photos, gives some details on coloring and markings in black and white tone drawings, several small color drawings.
Westland Whirlwind Mk. 1 from the Allied Wings series of booklets, published in France (no date). 54 pages, mostly operational history. Several color profiles.
The Westland Whirlwind by Profile Publications, No 191 published in the UK The color profiles may be useful.
Air Enthusiast magazine from the UK, July 1973. 10 pages 2-page detailed cutaway, cockpit drawing detail, 1 page color 3-view.
Air International magazine from the UK, March 1995. 7 pages, much the same as the Air Enthusiast magazine article listed above.
There is more, but like most of the above these show the same photos and stories/background history of the airplane.
The Whirlwind has been on my list of special interest airplanes for CL scale for a long time. I took care of my need to have a Whirlwind by building one for the multi-engine profile 1/2A scale rules used for the Tucson and St. Louis contests. The St. Louis rules require the controls to be exposed and no throttles. It was a fun build and it was successful, both in St Louis and in Tucson.
Keith