Will Kel-Tec send you a shipping label, or is this on your own dime? That saves a
lot of hassle (because you can then take it to
any UPS outlet, including the normally anti-gun "UPS Store"), as well as money, typically $50-$60. I've had the UPS agent (and the distribution center is 35 miles away) slice open the box I just sealed, ask me to take out the handgun that I just packed, and unload and show clear.
Ask your dealer if he can ship it by Priority Mail, using his FFL. Offer to pay the postage plus a few extra bucks, a case of beer or whatever.
If you bought the gun from him, he might even forgo the extra charge.
Another hint: put the gun in the box it came in and put that inside a cardboard box, with padding (e.g., wadded-up newspaper) to take up the space. If KT is like the other gun companies I've dealt with, they will send the gun back in a new box. Unless, of course, you like having extra gun boxes piling up.
When addressing the company, don't spell out the full name as an obvious gunmaker's name on the box is like putting a "steal me" sign on it. Just put "K&T" or something on it.