This has definitely been milled off. All the engines of this type I have seen of this type have had the brand cast into the case just like the 52 was cast into the other side. This was cast at one time and then machined off. There are a few engines with identical cases that I have named above and I am sure it came from that factory but I just don't know which one but that is not important. I will figure out how to get it running right even if I need to put on a different carb.