Wow! What a frustrating saga. Here's some suggestions to pursue in your free time (because life is so simple in little ol NZ) ...
1. Grind the master cylinder instead to fit the unflattened bars.
2. Grind the bars flat yourself and get them re-chromed.
3. Change to Harley controls.
4. Cut off the offending master cylinder and just jam your foot in the spokes when you want to stop - it would probably be less painful than what you've experienced.
