1973 Miyata MX-M. Shimano date codes probably won't be much help, as they did not consistently apply them prior to 1976. While the front derailleur is a Shimano Thunderbird, the rear derailleur is a Shimano Eagle. From the angle, I can't tell the version but I believe it's the Eagle SPO. The stem looks dangerously high, probably well above the instrertion mark.