Commando kickstart on dolls head gearbox

I have a pre-war inter with the rear set footrests on it. The footrest currently gets in the way of the kickstart that came on the bike. I have been searching around for a new kickstart and I reckon the cranked commando one would loop round behind the footrest and save me from having to mess about making the footrest pivot out the way. Does anyone know if the splines are the same size on the two different types and would it fit together?

Thanks

Andy