Mark:
I'm only a decade late in answering, but I too can't find much on Westwood in the Colt & Alison world. Here's all I have:
1. C & Whitten list it as a 1924 Alison design.
2. Paul Turner and Frank Pont list the design date as 1923
3. The Coshocton Tribune 6/1/1926 say it was in play in 1924. That would go with the above dates.
4. Mike Hurdzan revised three greens, all the bunkers, and some tees from 1980 - 84. He confirms the Alison pedigree.
Ship manifests have Alison in the country from March 7, 1923 through September 20th+/-. I can't find anything that gets a date for him coming back to the USA in 1924, but he must have been here.. I have records of him in NYC, Lakeville, Davenport and Knollwood between March 12 and November, arriving back in Southampton on December 3, 1924. So he could have been at Westwood either 1923 and/or 1924.
I'd be delighted to hear anything else confirming Alison being on site.
Anthony