Beautiful gun!
Your Marlin is from a more desirable era and I would say it is worth between $550 - $650. On a good day it might even bring $700+ because of the exceptional condition.
I have the same gun made in 1946 which I inherited from my Dad last year. Despite the fact that it has had THOUSANDS & THOUSANDS of rounds through it, it is actually in as good a condition as yours.
I used to own a more modern version built in the 90's (with the rebounding hammer) but when I got my Dad's Marlin and saw how much better the older ones are, I sold mine in a heartbeat!
There simply is no comparison to the 40's and 50's 39A - IMHO.
And IMHO there is no finer .22 lever rifle made. Marlin was sold about a year ago and from the scuttle-butt I see on the internet, they are struggling with Q/C in the new plant down South. I guess a lot of their old time employees in CT did not move down South with them, and they are disparately trying to get their act together.
Unless you really need the money or truly have no intention of ever using it, I would suggest keeping it. While not rare, yours does seem to be a really nice one.
Chief38