Hey Bart, there are some places in NYC that make cherry (and sour cherry ) pies.
1.) Bubby's http://bubbys.com/index.php/Store/
Excellent Sour Cherry pie if expensive. $7 a slice but I do indulge in it every so often as it is one of the best I have ever tried. I don't have 100% confirmation that these are fresh cherries but after having eaten this a few times I am very certain that they are fresh.
2.) First Prize Pies http://www.firstprizepies.com/shop.html
I'm not sure if she makes a cherry pie, but she does do seasonal berry pies so it might be worth an email. I met Allison a few weeks back and tried her S'Mores and Bourbon Ginger Pecan pies which were terrific!
3.) Four and Twenty Blackbirds http://birdsblack.com/?page_id=39
A new place in NYC that I have wanted to try.
4.) Pies-N-Thighs http://www.menupages.com/restaurants/pies-n-thighs/menu
Another place with sour cherry pie
Best to call ahead on these to verify that they use fresh cherries before making the trip. Hope this is helpful.