R1 4xv gearbox!!

Hi all. Does any one have or know where I could get a gearbox for my R1? My box has seized up and stuck in second :frowning:
I’m not 100% sure its the box but I was having the annoying second gear slip previous to it seizing. Can anyone point me in the direction as to where I can get one from.
Thanks folks.

if it still rotates but only in second, I’d say it’s just your internal selector that’s broken, not the whole box.