Try this link and you'll find plenty of information. I own an old Marlin Rifle I bought back in 1995. They made some great varmit .22 caliber rifles. Sold a bunch of them too. 11 Million or so.
About the manufacture date of your Marlin 60. Circa 1972 the first 2 numbers were the year of production. After that you subtract the first 2 digits of the number from 2000 and that gives you the new style production year. 20625387 is your SN. so 2000 - 20 would make it 1980.
This bit of math is only valid for production model made from 1971 to 1999. Prior to 1971 or depending on who talking too.. the first two digits indicated the year it was made. Starting in 2000 they went back to the old way.
Of course no one would ever steer you wrong on a gun forum, on the internet. Unless of course visitng New York City, with a permit to carry concealed, and want to know if NYC will honor it? Good luck.