Sachs made a few engines years ago..They were to be sold through chainsaw dealers...I saw the literature but never saw an engine...There are no "Sachs" engines, just engines made with Sachs cranks, pistons, and cylinders...Making a crankcase and using these parts does not make it a Sachs engine...Same with Husqvarna, there are engines made with Husky parts and machined cranks...They are not Husqvarna engines...Same with BME, Keith uses Echo parts but does not call his engines "Echo"...Many engine companies tend to keep the origins of their products hidden, since "industrial" engines are not deemed good enough to power high dollar miniature aircraft..(IMHO)
I think A&M started out with Sachs cranks and changed later...The MKII A&M engines were the ones Brison improved on...The A&M MKII engines had cantilever cranks made by, or for, A&M....