Here's a pic from the evil bay ad. The actual numbers on the casting are a slightly smaller size than what's on the original on my car, I think. And in a slightly different location. The other extraneous numbers aren't the same, but I figure that they're some sort of production numbering system. The seller says the paint/coating will burn off. Also, he sells a lot of FE exhaust manifolds on ebay, but noted that that this particular casting number is difficult to find. So I lucked out...but I'm still crossing my fingers that everything will be as needed when it arrives. Here's the pic :
The 'Circle-F' is the Cleveland Casting Foundry mark. The '9A L' in the raised oval with slotted screwhead impressions is the casting date, in this case 9=1959, A=January, L = 11th day of month, so manifold was cast on January 11, 1959.