You have the mufflers but they are missing the felt? Or, you need the entire muffler assemblies including the felts?

1964 was the year of red felt on the baseball bat style mufflers (tone controls). The felts on all BB mufflers were riveted in place. I don't see how they could ever go missing!

I've never heard of replacing just the felts and I have no idea where to look for the right kind of felt.

Replacing 3 red felt BB mufflers may not be that easy. You might have to watch EBay for awhile. If you aren't particular, then it might be much easier to replace them with white felt ones until you can find all the reds. However, there are some parts guys on here who might have some. mlvbs and vadrums both have lots of spare parts, I think. maybe one of them will see this and respond. Or you could send them a PM here via the forum.

Burger Kin

P.S. There are no "new" Baseball Bat mufflers. They are vintage items ONLY! In other words, you can't order them from Ludwig anymore. They are long gone. You probably already knew that, but I just wanted to clarify.

And just to add to this thread, too:

Red felt tone control assemblies can be VERY pricey to replace. I have seen them sell for $100 each. They may be more than that, now, for all I know.

Yes,

I do have them...