After thinking about this for a while I am beginning to think your gun was made in 1993. On "MOST", Marlins made from 1969 to the present you subtract the first 2 digits of the SN from 100 to get the year of manufacture. The 2 links above, wwwarmscollectors.com, and wwwoldguns.net are the same but stop at 1990, but the code still applies. For example if the first 2 digits are 22 your gun would have been bade in 1978. If they are 98, then your gun was made in 2002.
On some models this code does not apply however. I have one of the stainless guide guns in .35 rem. Marlin only made 500 of them in 2005 and my SN is 336SS3XX
Marlin made a limited run of 336's and 39's with the color case hardened look on them around that time and you could have one of them. If so they are petty rare although not old.
Does your gun have a crossbolt safety, checkering and round bolt? If so it is a newer gun.