The real question is whether you have CCW rotation PTO. If you do, good luck finding one. If you have the adapter to take you to six spline CW rotation, I could put one into your hands that's intended to work on a machine like the beaver.
I don't feel good about it, but I just posted my Satoh 370 with a rotary cutter on eBay. It is the 16 spline with CCW rotation. I have a feeling the mower might worth more than the tractor.
I was so caught up in feeling bad about selling my tractor that I forgot to help with your question. The brand of rotary cutter that I have is Carolina or something similar. There is a picture with the logo on the eBay listing. I've never seen that brand or heard of it before, but maybe someone in here can identify it. Maybe that will help with your search.
i appreciate the help. I have decided that I am going to clean up all the downed limbs and debris where I need to mow and just use my kubota zero turn to do the job. The satoh is a nice little tractor but I simply don't need it. the kubota zero turn is a beast. My satoh does a really nice job with the finish mower and i completely rebuilt it with new spindles and blades and pulleys but it is no comparison to the kubota. I also have the factory rototiller but I don't see myself using it either. I am going to sell my satoh and the attachments. Better than it just setting there not being used.