Richard,
In my experience, the moisture content is key to making sure that door stays straight. Get it to 8% and seal it right away. and at 102" tall, you would need perfect conditions for reclaimed wood to stay straight. Ive made over 2000 tables from reclaimed cedar, pine, doug fir, and white oak, and I've come to realize that you cant fight mother nature when it comes to old growth wood. It does what it wants, and doesn't care about your project.

Why will the wood warp?

Wood warps in response to changes in moisture content. If you are the responsible party, then it is your job to insure that the wood purchased is at the proper MC, or you will have to do what is needed to get it to the proper MC. 2 weeks on the job acclimating will not give the assurance I think you will need. Meter each and every board in several places before you start the project. One board that is not at your target MC can cause problems. Proper MC and EMC can be determined by charts as found in Bruce Hoadley's book Understanding Wood.

Solid wood doors as in the photo usually have horizontal battens on the backs that are fastened to allow wood lateral movement. Surface mounted or inlaid, dovetailed or decorative, they should be considered essential. The doors will still move with the unavoidable seasonal variations in relative humidity, so you will need to know that range so as to plan gaps and clearances correctly.

Make sure they kiln dry the reclaimed wood to kill bugs before you get it. If they don't, you may get a call in a few months asking about the little piles of sawdust on the floor under the doors. Powder post beetle eggs love to hatch out in the nice warmth of a home.

Rip and Flip others will discount this, just saying technically it has to alleviate warp.

Thanks All.

David, I like the idea of doing some kind of decorative inlaid battens do you have any more details or thoughts on how this might be achieved?

Thanks

Richard

Rip and flip was a strategy that came about as a way to deal with boards cupping across their width as they responded to changes in environmental humidity. The rest of the story also mandated that no piece of wood be wider than 3". This was during a time when most wood was air dried or in the early dries of kiln usage.

The 'rule' was extensively promoted by Jerry Metz as a keystone of "Metz Rules" that he offered in 25 years as a columnist for a woodworking journal.

I feel that current thought is that the two steps mentioned in the old saw are no longer needed, since cupping across width is not a problem with solid wood that is used inside and dried properly.

As asked above - Why will the wood warp? Understanding this will help a woodworker concentrate their energies and resources where needed instead of blindly adhering to uneccessary and outdated rules.