A Johnson outboard, model number MS39, would be a 1939 model, 1.1 hp. As for the value of this engine, I suspect it would garner some collecter interest. I have not seen this model up for sale in several years, so I'm not certain of current value. You have a nice engine there, take care of it.
1985
Johnson outboards, model RDS-24L, would be a 1962 year model, 40 hp. the boat motor is a 50 hp.
1963
1969
1980
1986
That in for a 1984 Johnson 70 hp outboard engine.
Model number J150OLEVR is a 1997, 150hp Johnson outboard.
1972.
CD 24 is a 1967 model.
1965 18 hp
Johnson outboards uses the engine model number to determine the year model of the engine.