Bill,
We've discussed this issue a zillion times.
But, I'll give you the short version.
1. The US Amateur was held there in 1936
2. There's an ABUNDANCE of aerial and ground photos circa
1936 that show the golf course exactly as it was.
The golf course as it existed circa 1936 is well
documented. That can't be said of other sentinel years.
3. By your theory, do you restore it to Emmett's work,
Travis's work, some club changes or a combination of
all of the above ?
4 Do you restore it to 1897, 1898, 1899, 1905, 1906, 1913,
1915, 1920 or other dates when changes were made to
the golf course.
Garden City's design history/ evolution is complex.
With the overwhelming abundance of evidence available circa 1936 and the hosting of the USGA Amateur in the same year, 1936 is a prudent choice.