Welding Tips and Tricks

A little back ground, I am a service engineer and fabricator in the marine industry. Here recently I had an anti heeling pump come through my doors with an impeller that has been through absolute hell. Incredible amounts of cavitation and harsh working conditions has left the blades and "hub" of the impeller covered in deep pits. Customer wants it repaired as a new one would cost upwards of 5k, what would the best method be to repair this as cheaply as possible? Acetylene brazing? Tig? Scrap it?

NS 16570 Grade CuAl10Fe5Ni5 - Cast Copper Bronze Aluminium Bronze

Also propper filler would be a plus as I do not deal with this material often.

Can you post some pictures? How big is it? Where are you located?

You can get Silicon Bronze, or Aluminum Bronze filler rods for TIG. The Silicon Bronze (SB) has a color between copper, and bronze. The Aluminum Bronze (AB) is more of a silver color. I would probably go with AB because it is stronger than the SB.
I use AC current with AB, and DC with SB.

I don't think he has been back since I posted an answer. I was hoping for some pictures.