I think it is posible to replace the cable without taking all that off. I replaced mine when I first got it by taking everything off. Because I couldn't tell were it went. After it was done I looked up from right side, inbetween the motor and front hanger and found a passage with direct acceses to the tach holding screw. Looked like if you had a long enough screw diver, you could get at it. I would be worryed that the screw would fall off. So maybe if you glued it to the driver, it would work. Mine broke last night. New one coming. I'll try it this time. Damn cheap cables.
I have enjoyed reading about this trip. Sounds like a blast. Please keep us posted.
Cheers, Michael