I have three Grafmatics in nice condition and two beaters for sale. They all have straight septums and cycle nicely without jamming. One of the beaters has a (replacement?) milled composite end piece. I guarantee that all of them work fine and will cheerfully refund your money if you're not satisfied for any reason.
So tempting...I wish this had come a long a day or two later, as I am watching something on E-Bay right now that I probably will not get, but want to have the option of bidding on if it goes for low enough...