Machinehead problem on Fender Dual Professional

[alan121234]

Hello, Ive just joined
I bought a Fender Dual Professional double 8 string circa 1950 some years ago knowing that one of the machine heads didn't work. Ive looked at the problem from time to time and given up on solving it Foe some reason the cog {or gear} is too small. Its smaller than the others . I thought it would be a case of buying the right size cog but that's the problem. Ive been unable to find a cog the right size I figure I need one the same as those used by Fender in the 50s . Does anybody have any ideas ? I can't replace the machine head as its part of a strip that is brazed onto the tuner pan .
Thanks in advance for any advice
Alan

[JohnDavisStringsHere]

some close up pics may help.....