I have frame number M1F28081. I bought it as a frame on Craig's list for $50. The seatpost and stem were stuck big time, I had to get the seatpost drilled out by a frame maker. It had no decals except SHOGUN on the downtube and no headbadge. Nice pinstriping. It had Shimano 600 Arabesque brakes, crank, and shifters. It's a very well balanced bike and fun to ride. I gather from reading here that it's a 1981 Shogun 700 but I don't really know.

Here is a link to a ride report from a 300k Brevet I did on this bike: 3 Volcanoes 300k
I have since resolved the handling issue by stabilizing the front bag better on the rack.