I hate to admit that I can't commit to anything at this point, but I'd love to ride along.
In my opinion, you can't tour New England without including some part of the White Mountains. The Kanc. is nice but not the only nice road, especially if you're not afraid of dirt roads.
Also, I feel you must include some part of the New England coast. Notable towns in my region: Portsmouth, NH, Newburyport, MA, Wells, ME, etc. Some nice routes near these towns. I love 1a along the NH coast, but you gotta hit it at the right time to avoid traffic.
Of course, Maine has some great coast to offer, though I'm less familiar with the routes near the water. If you get above Portland there are some nice places off of Rt. 1 like Friendship. There are several great towns along Rt 1 all the way up the coast, but man that road can suck if you plan badly.
On a side note, I'm putting together a day ride from Portsmouth, NH, to roughly Plymouth, NH, following what would have been called the Province Road in the 19th century but is now just a collection of smaller roads through some pretty areas. I could see including this if the New England tour was to need a route from the coast to the mountains of New Hampshire.
One more thing: I could offer up my dad's garage as a pit stop if anybody needed one. I've got the basic SOHC4 tool collection including a Carbtune there. We're just East of Concord.
I'll keep checking in here to see where you guys are at and if you need a local impression of a route or area feel free to contact me.