Sorry, I've been VERY slow on this one. I don't know if GE would have HAD a model number for this locomotive: "B-B-46/46-4GHM844" (I assume this is from the locomotive's builder's plate?) is a description: B-B means(*) BB trucks, 46/46 means the total weight is 46,000 pounds, of which 46,000 is on the driving axles (GE still uses this format on its builder's...er...stickers, or at least did until very recently), and the last bit says it has four traction motors of model (G)HM844. (A lot of GE numbers seem to get G as a prefix, and I think this particular motor might be referred to either as GHM844 or just HM844 dpending on where you look. Railfans are familiar with big GE traction motors with 700-series numbers, like the 731 used on Alco switchers and the famous 752, but there are several other number-series for traction motors. HM series motors were used on some very early and mostly small locomotives.)
(*) Disclaimer: this is a (semi-) educated guess on my part: I DON'T have any vintage GE documentation to back me up.
Something that I think might be interesting to at least some railfans/railroad historians would be a full list of the GE traction motor types with some comments about their characteristics and applications: this ought to be made available on SOMEBODY's WWWeb page.