Led, the last post regarding this was a month ago...it was buried until you dug it back up.
Anyway, moving on..............
RG is correct regarding the neck angle considerations, Zeb. You'll require a neck angle of sorts.
If it wasn't for the fact you're using a Bigsby, I would have suggested sinking your T.O.M. into the body.
Draw out your neck to body to bridge join on paper to a 1:1 scale and that should give you the good oil.
Either way you'll need to angle either your neck tenon or body mortice, otherwise you'll have a whoppingly high action.
Cheers, Stu