I don't see a cable hooked up and it looks like the chain is in the inside chainring. Am I missing something?
If this is the case, I can't imagine being able to shift to the outside chainring.
Is the braze-on mount welded on or mechanically fastened?
If it can be removed, you may be able to use a bottom clamp/top swing derailleur. While it may not be something you want to go with, maybe an old XTR.
John