According to the Bluebook, Marlin Mod 90 can be dated before or after 1949 by the side ribs on the barrels. supposedly guns before 1949 did not have side ribs?? Also they have a partial serial list seem that post war guns had a letter prefix, the first letter they show is E for 1948, this could explain the low serial # if they started over each year. Don't take this to the bank, who knows if it is correct.

Jim

I learn something every day, and a lot of times it's that what I learned the day before was wrong