Yep, bitsa for sure, the stamped number is nothing I've ever seen(or noticed) on a B&S engine. Probably a number stamped on by the refurbisher as a way of keeping track of what's been sold for warranty etc.
As for the spacers, nothing uncommon amongst certain manufacturers in order to space up the engine so the blades don't protrude below the lower edge of the base.
If you take a pick of the underside we can see if it has kept the original victa blade setup or something else.
