Spanish Li special gearbox

The Spanish Li special gearbox ratios look to be a mix of
Italian Lis 1st-2nd and 3rd gears with an Italian Li150 4th
Will the loose 1st-2nd and 3rd cogs fit in a late pacemaker box?
Will the loose 4th gear fit an Italian Li 150?
Looking at the details in stickies book, it seems possible -but with all things lambretta you never know until you’ve tried it.
Has anyone tried this or know that it’s been done
Italian Lis 1st-2nd and 3rd gears with an Italian Li150 4th
Will the loose 1st-2nd and 3rd cogs fit in a late pacemaker box?
Will the loose 4th gear fit an Italian Li 150?
Looking at the details in stickies book, it seems possible -but with all things lambretta you never know until you’ve tried it.
Has anyone tried this or know that it’s been done