I am right there with you!

Ah. There's the rub. In my experience, not many of these folks around and available, esp. ones who will a) work with a builder/owner and b) is qualified to sign off and stamp plans.

Another question with old timbers (I suspect) you may have to contend with is getting them approved/graded by a local inspector, assuming your local codes warrant that.

I would imagine this process is even more difficult if your beams have any imperfectiong, i.e. old mortises, in them that may make them structurally weaker.

I am heading down this same path, and amalready anticipating beauracratic nightmares with the local building "authorties".

Don't let me discourage though. Good luck!