After working their website to the bone, I finally called the parts hotline for messicks. Very helpful people. They did find a warehouse for obsolete parts that has the entire knotter assembly, but they're wanting $800+, and it weighs 70 lbs, so shipping is going to add a good bit to that.
On a brighter note, my friend had an almost complete knotter assembly off a ford baler, and the cam gear looks good on it. The trick right now is getting the sucker off. The rest of the assembly is rusted into a solid piece, just about, especially around the shaft. I'll peck away at it till I get it off of there, and maybe that will have me back in business for spring. Thanks for the help.