Now I "get" it. On my 48, you have to push the exterior adjusting bolt in towards the wheel cylinder to engage it, it's spring loaded. The bolt and cog wheel on mine are steel, so tack welding wouldn't have been a problem.
You'll have to jam something between your backing plate and leaf springs and repeen your cog wheel with a good center punch if they are made of dissimular metals. Could you make a new backing plate bolt and wheel with hardware store stuff?
Scott