The correct number (according to my new friend) is 37.
Charles, I was initially surprised that there are that many classic courses on the list today that weren't back then. The three I could name off the top of my head were NGLA, Fishers Island, and Crystal Downs, but I guess there are a lot of shortish Raynor courses on the GOLF DIGEST list now, that weren't before ... Camargo, Shoreacres, Piping Rock, etc.
I do not have the 1975 list to verify this last bit, but my friend said that the architect with the most top 100 courses in 1975 was ...
Dick Wilson !
If so, it is AMAZING how far his star has fallen. I guess back then he would have had NCR, Meadow Brook, Coldstream, Laurel Valley, Bay Hill [maybe], Pine Tree, Doral, Cog Hill, and La Costa.