it might be just me, but i've always though that Gibsons Les Paul warm tone and overall sound characters comes from its huge body mass.
i wonder how a flat 1" Les Paul will sound like.
on the other hand, i know that my Schecter C-1 have great warmth as well, and its neck and body are from mahogany, and its not as half as heavy as a LP.
I think that if you'll just get a good, dense mahogany blank for the body, and get that neck you mentioned first, from maple, it would be full of sustain, not too thick (but yet pretty heavy) and the maple neck would add a bit of attack to your sound.
Just for example, i've tried one guitar from one piece mahogany, and 2 original Seymour Duncan pups, washburns i think (really not sure) that sounds like crap. i bet those pickups and overall specifications would sound great on a good piece of mahogany.
And like you've said, just try, you can prove us all wrong!