It was made in the year 1968.
The letters AD which is a prefix to your serial number indicates that your Marlin rifle was made in the year 1968.
According to a Marlin owners forum (the Revelation 200 was made by Marlin), that was made in 1966, if the serial number is on the lower tang. If it's on the upper tang, it was probably made in 1969 due to a federal law that dictated where the serial number would be placed. It's also supposed to be extremely interchangeable with the Marlin 336. The Revelation was a price competitor rifle and the stock was probably made with Birch instead of Walnut. From what I've read, it's a good rifle.
Marlin
With the serial number provided,your Marlin .22cal rifle was made by Marlin in the year 1985.
The H prefix to your serial number indicates that your marlin model 336A was made by marlin in 1951.
The K prefix to your serial number indicates that your marlin model 336RC(regular carbine) was made by marlin in 1953.
your marlin model 1897 was made by marlin in 1903.
Your serial number indicates that your Marlin model 336W was made in the year 2009.
Your Marlin model 780 was made in the year 1977 with the serial number that you have provided.
The W prefix to your serial number indicates that your marlin 336 was made in 1963.
Your marlin model 39A was made in the year 1980,with the serial number that you have supplied.
Your serial number indicates that your Marlin model 781 was made in the year 1972.