Bit of an old thread but I have a SD '59 bridge double black that doesn't work.
Been in the parts drawer since I buggered it up a few years ago trying to solder it with my failing eyesight :)
Drop me a PM if you're interested. But I don't think it's a simple fix - not as simple as the SD Anituities I buggered up at the same time - with those I'd just soldered the signal wire to the earth shield - and ended up just cutting a few cm off.

