Using transformer gain like first watt M2?

I was wondering whether the first watt m2's use of the transformer as gain is panted, and whether I can use that idea in a school project of mine. I am designing an amplifier and I have always been very interested in avoiding negative feedback, but it seemed damn near impossible or at least very hard to implement, until I saw the m2's design. I think it's an ingenious solution to the problem and would love to incorporate into my project. But at the same time I wouldn't want to use a piece of IP that isn't mine, but I couldn't find any info on whether it was patent or anything of that sort. So does anyone know if I would be able to use this idea?