It actualy looks like an A&M . The A&M preceded the Brison and was bought out or taken over by Brison . Some of the A&M engines used an aluminum rod ,some had machined steel rods (both were a light gray color rod). The better versions versions used a sachs crank and rod and some were modified by Brison using the Brison cantelevered crank and sachs rod (and bronze or dark colored rod)
.The aluminum and/or machined rods have been known to either shake alot or have failures.