If there's anyone still here, I'm looking for input/direction for the following:

Tenant improvement railing project being built to AWS D1.1.
Contract document require railing configuration using 1" X 1" X 1/8" Sq. Tube rails welded to 2" X 3" X 1/8" Rectangular Tube posts.  Post are A500
1" X 1" Sq. Tube is only available from my distributors in A513 which is not an AWS approved metal.
All A513 to A500 welds will be fillet welds.

Questions:
Can a fillet weld for a NON-Approved metal [A513] be qualified by PQR?
Can the PQR be qualified by Macro-Etching alone?  If not, what testing would be required?  It's unlikely the project would justify a large expense in procedural qualification but if it's a simple macro-etch it would justify the PQR.
Suggested AWS D1.1 figures to look at for the PQR?  Should the two tubes of the two materials just be set up as they will get welded in the shop and field, do the weld, cut,polish,macro and examine?
If yes to the above testing configuration, we would develop the PQR for both SMAW and GMAW short circuit.

I am certain and confident the weld can be made to pass a visual examination/macro etch with both processes and have no doubt they will fully serve as needed, but I don't know if the un-approved A513 is even eligible for testing.

Thank you for your suggestions.