I recently purchased a touring frame that I am having trouble identifying and would like to tap into the collective knowledge of the forums. I've looked through countless catalogs, photos, and serial number lists but haven't really found anything that narrows it down. I've felt close but then notice a minor detail that differs (fork crown lug shapes, lack of front rack braze-ons, etc.) from the example.

The friend I purchased the frame from thinks it is a 1984 Miyata 1000 but wasn't quite sure. As you can see below, the frame has been powder coated at some point so no decals remain. It is a 54cm frame that fits 27" wheels. The front spacing is 120mm and the rear spacing is 126mm. There are three bottle mounts. The serial number is M6-G2241 (see picture below for location). Any ideas or help would be most appreciated!