Exactly what surfmac211 said.
The Nat Sherman 536 and 649 are both amazing. I order them 1 lb at a time. Definitely call the store in NY. If you get the mail order division, you have to tell them you need the actual store as you want something they only have there - the 649.
If you like the 536, you need to get the 649 too.
I smoked both of them when I went to NY last year in November to shoot this video and article on Nat Sherman:
http://pipesmagazine.com/blog/pipe-manufacturer-retailer-spotlight/nat-sherman-an-icon-in-luxury-tobacco-for-80-years/
If you just watch the intro of the video and you see me saying that I like the tobacco I just lit, it is the 536.
The next day, I did the Michael Gladis interview and we both smoked the 536 and the 649. He liked the 649 so much that I gave him my bag.