Couple different Model B fuel pumps

[37 Coupe]

The fuel pump on the engine in my '32 five window is something I just took notice from after just owning the car since last Oct. It doesn't look like the original ones in the '32 book.It is marked AC and Made in England,so some sort of replacement or one that fits other engines I imagine. I am not concerned about what is correct or not just curious. The other picture is of a core I bought as a Model B and hope it is before I go any further for just a shelf spare other pump works fine so far. I think somewhere I read the original or replacement pumps were "G" series? The core pump has very little markings on it but does show AC and what looks like an "H".Were these a later manufacture? Or maybe this is not even a Model B pump. It looks the same where it will mount but upper part to me seems larger than the domed one on engine.Thank You.