well i dont know what setup i have...to get reverse and 1st you have to push the stick in but ive seen on the diagram for the 5 speed box this isnt the case.
in the manual it shows the 4 speed with a metal rail nearly the full length of the box front to back but the 5 speed has just a small rail to stop you putting it into reverse without the downward motion.so im thinking mine had been upgraded to the 5 speed at some time and they hav'nt bothered with the selector box
also i think on mine its possible to put it into first but it isnt locked and you can go straight into 3rd with a slight nudge on the gear lever
E D I T...just been out and tried it and when it jumps out of first into the 3rd position it still stays in first so thats not too bad