Bits of the design are interesting, Ty. The layout is the same as the Alroh Imp, but a lot cruder. Since my Imp is from 1963, and the one you've just documented may be a bit newer than that, it seems like it may be a bush league "me too" copy. I had the vague idea that the center-hinged frame that gives the height adjustment was patented by Alroh, but if it were your discovery would seem to be an infringement, so perhaps they didn't patent it.

I like the general idea of the clamped piece of wire cable used as a cutting blade, because it would be cheap and easy to replace, but I doubt it could be executed in a way that meets my safety expectations, and most people wouldn't like the wide slots down the sides of their lawn (though personally I think I'd rather like it).

Here is my Imp (before I brush-painted it to cure the rusting):
[Linked Image]

Here is Alroh's brochure image of the Imp (which seems to be a later one than mine): [Linked Image]