Just had the new bosses brazed on! Took them to a local frame-builder and he had them done in about 20 minutes.

Here's the whole brazing video:
Some still-pics of the process.


Sanding the area all around the tubes

Sanding off the bosses

Adding the bosses onto the tubes, along with plenty of silver flux



The finished brazing job

M5 bosses attached, ready for frame lock!