Nice lookin' Tele ya got there!
I've heard of people using shoe polish to tint necks, but the problem is that there is a very tough poly coating on the neck. The polish doesn't get into the wood and will eventually wear off, usually onto your hands.
Sunlight will do it over time, or there is the tried and true method of stripping the protective coating off, spraying on a coat of Neck Amber and clearcoating over that.
Here's a link to the Guitar ReRanch. http://reranchstore.stores.yahoo.net/fennecam.html
I've never had to reslot a nut to go to 10s. I've just put on new strings, tuned, and let 'er rip. Here's a link to Stew-Mac for some nut files, though: http://www.stewmac.com/shop/Nuts,_sa...d_saddles.html