Yikes!, that is a lot to throw onto someone's shoulders.
Try to locate a lab that will help you with performing the mechanical testing. (ie. tensile pulls, bend testing, etc.)
Unless you have the testing equipment and a machine shop at your disposal to perform all of this in-house, I would find a lab that can help with all of that.
I don't have a copy of D1.6 handy at the moment so I can't help guide you through the entire process right now.
Maybe someone will chime in that has a copy of D1.6 handy to reference.
PS. If you are the welder who welds out the procedure test coupons, if the testing passes, so do you for the positions, thicknesses, process used...etc.