Welder performed a GTAW performance test on 2" sched 120 CuNi (P-34) to CuNi (P-34) using ERCuNi (F-34) Filler rod.  I need double checked on if he is qualified to weld a Carbon Steel slip on flange (P-1) to a CuNi pipe (P-34) using a ERNi-1 filler (P-41).  I just need to know about the filler and base material combination.  Per QW-403.18 as permitted by QW-423 reading under 423.1, qualified with P-34, qualified for any combination listed on the right which has P-1 and P-34.  So it's looking good on the base material side of things. Correct??
   For filler material, QW-404.15 reads I can change F#'s as permitted in QW-433.  Under 433, qualified with F-34, qualified for F-34 and all F# 41's thru F# 46's.  So it sounds like I should be good on the filler material as well.  Am I reading this correctly?

Thanks,