Thanks for posting this - I've liked Leiter's work for a long time, but I was unaware of this website. I suppose I should have guessed that there would be such a site for his work... (but I hadn't).
I can't remember now how I discovered Saul Leiter's work, it might have been through his book, "Early Color" or Thomas Leach's documentary (trailer below), something I watch every now and again, especially on cold winter nights! In the documentary you see Margit Erb, the founder and director of the Saul Leiter Foundation, and she assisted Leiter for over 18 years so she know him pretty well!. If you're at a lose end you might enjoy this talk Margit Erb gave in 2016: