Interesting question, one that held me busy for a good many years. Between 1988 and ca.2002, when I collected data on surviving Sherman tanks and related AFVs, I amassed 1,000+ records on surviving Sherman tanks and related AFVs around the world. One record could represent up to several dozens of tanks, so 10 years ago there were far more than 1,000. During the past decade, with the vastly expanded means of communication (internet, digital photography), many more have been discovered and disclosed. I lost count but would not hestiate putting a bet on 1,500.
HTH,
Hanno
SHERMAN REGISTER