Chris, I have done 2 bulkheads and you dont need to build a jig. Just tell them not to quench the bulkhead in water after the galv process to cool it. Tell them to air cool it. Nothing ever warped for me at all.
as for the doors, I removed the skins and galv the frames. then put on new skins and seam sealed them too. they will never rust now.
Legend in My Own Mind.