That I don't know unfortunately. I used a TRX third gear, straight swap over to my mk2a 8fiddly. You might find your answer by looking up the parts numbers of the 1st gear/axles.
If I were you, I'd swap your mk1 gearbox over for a mk2a gearbox, if you can get one at the right price. Very similar ratios and it's a better quality gearbox. It's also easier swapping over complete boxes, than swapping bits of 'em over.
Okay thanks.
I've looked at a couple of parts lists, but can't see if I would need the 4tx shift drum and arms together with the gearsets, or could I swap simply the 2 gearsets from the mk2 to the mk1 ?