Your rifle, the Model 6083 was made in 1983 for the Oklahoma Tire and Supply Company (OTASCO). Marlin made a number of commemoratives for OTASCO over the years. There was also a Model 3083 made that same year and it is a Marlin Model 30A with the same medallion in the stock. Your rifle is a Marlin Glenfield Model 60 which is the same gun as the Marlin Model 60, except it has a walnut stained hardwood stock (usually birch) instead of a walnut stock that the regular Model 60 would have had.
I hope this helps.