Unfortunately the mounting holes are incompatible. In addition, the mounting holes of the knob adjustment dampeners made in the later years of Ludwig production are incompatible with those of the earlier production, having the small screw hole on the top instead of the bottom as in the earlier original tone controls. In my opinion, the original baseball bat style, when reset and properly adjusted isn't really that terrible, and you should leave it for the sake of originality and for your drum's resale value as an "authentic" Supraphonic.

It has been my experience that each and every Ludwig knob control tone control was poorly designed, so that the disc covered with black felt becomes loose from the supporting lever arm and rattles terribly both in 'on' and 'off' position. I've always had to glue the discs down to the lever arm using mixture strength epoxy glue in order to utilize them without hearing a terrible "buzzz" emanating from the drum...a minor hassle, admittedly, but still a hassle. Congratulations on being a Supraphonic player, and good luck in the future!

You can use the round knob mufflers in place of the baseball bat muffler. You will need a flat washer between the shell and the muffler on both sides since the bat muffler has a larger top hole.

Mike

Another option is getting the Canopus baseball bat repro. From what I understand (I've never had issues with my BB mufflers) they've fixed whatever issues those are. I've got one repro on a drum and it's great. Has two stop points, doesn't move an inch either.