I've got a '78 Raleigh sports that I'm rebuilding and I'm running up against a problem with the brakes due to the fact that the inner locknut on the pivot bolt of these Weinmann center-pull brakes is super-thin like a cone nut. Getting the pivot bolt tension correct is a PITA without a super-thin wrench to hold the inner locknut when I tighten the cap nut on the outside.
Nobody makes a 10mm cone wrench that I can find. I've never had good luck ordering tools from an LBS -I guess they aren't always the most helpful. I can't even find a mention of a 10mm cone wrench on the Park Tools website.
I might just have to cut out my own wrench out of some sheet steel. I've never run into this before.