Had an email from Draganfly which helps explain the different bush lenghts.....
Hi Andrew, from 1960 the A group gearbox was indeed fitted with two of the
67-3073 long bushes. Up to then, the bushes you ordered were fitted. Should
not be a problem though.
Cheers, Mick.
I have started the strip down tonight and will be pulling the gearbox apart tomorrow evening. Fingers crossed. Oh the play in the shaft is horrible.