You could also do away with the original bar entirely, and fashion a fatty of a flat /wide bar, more remnicent of a Bigsby arm, and have it sweep back a tad to the general mount position you're proposing, then sweep out, arcing gracefully up, again, like a Bigsby...that way you could go polished or brushed aluminum and mount just the bar to the original mount point on the Kahler, and not some multi-piece contraption.
Think *kind of* the shape of a square-root bar in mathematics, yet more curved with the small line segment being the mount point and you're in the ballpark with what I'm suggesting.
IF you went with a thicker arm, you could even have it engraved with a subtle filigree / vine motif to carry on the theme of the bass.
Just thinking aloud...I hope not to offend, but just to offer suggestion / alternatives.