Please excuse the presence of a non-biker but I'm trying to help my neighbour.
He has a '61 Leader with a gearbox problem. Apparently the initial symptoms were that the bike would jump out of third gear & occasionally the gear shift would stick in the down position when changing up to third. This came to a head with not being able to select third at all. He now has his gearbox in bits but can't actually find a fault. That said, & by his own admission, he's no mechanic.
So, can anyone suggest what the problem may be or recommend a gearbox specialist in Essex/Suffolk?