need MS DOS 3.1

Does anyone know where I can find MS=-DOS on 5 1/2 inch floppy disks? I have a working Leading Edge Model D and need the op system. Believe it or not, I was quite the batch programmer way back when. Also, I am looking for a Leading Edge Model 86. Thank you very much, Joe  Consciousness affects the medium. Think happy, be happy, and happiness will follow you.