from the looks of the pic looking down into the tower, those grooves that the shifter rides in should be sqaure, looks like thats whats worn. and letting the shifter come out of the rails? floppin around means its out of the rails like you know, if its in a gear when it comes out then you try to shift it, it usually can slide another fork into gear. there should be detents and balls on the rails to keep it from going into two gears at once tho...id say the top cover is worn out more than the shifter itself... when the shifter itself used to wear out we used to build them back up brazing them back into shape,,it would last awhile... also, ive never heard of top cover matched to a transmission..think someone was tryin to sell something..??? ive mixed them with no problems..... and nothing in a manual says that....as long as they are both 420's..the only difference i can think of is maybe the post for emergency brake handle... and of course the rear cover can be different...
