Associated Timber Services is just off the A1 near Colsterworth (Honey Pot Lane) and apparently offers kiln-drying, but I don't know if they'll kiln-dry other people's wood or whether they'll want you to buy the timber from them as well. You could call them up and ask?
(I don't know anything about the company that isn't on their website, I just looked them up after missing the A151 turning on the way to work recently and driving past their place!)