Aprox. year of manufacture?

[FieroCDSP]

Hi folks. My friend wanted me to see what I could dig up about his .22 rifle (he's not all that gun-savvy).

It's a MArlin mo. 81-DL (exact markings "MODEL 81-DL-22 CAL-S-L-LR" with a horizontal line with a center dot following it).
23" barrel w/ shallow rifling (micro grooved?) with 5 lands.
Ramp front sight with brass bead and 2 mounting screws. Pinned windage but maybe be after-market. Otherwise it's a dovetail.
Folding notch sight (leaf with stepped ramp, both steel)
aluminum magazine rod with steel follower
No S/N, no letter markings.
2 piece trigger, bottom is stainless.
sliding safety with 2 screw "detent spring"
tapped for on left side (for peep sight?)
Stock is unremarkable except it has a hard plastic butt-plate.
The poor thing has a lot of light surface rust and the stock is badly cracked down the length of the forward grip, all the way back to the trigger guard. I know it's pre-68, but it seems older. I've ordered a stock for an 81-TS for it (hope it fits or can be made to), but it's mainly a plinker. Just looking for some rough history on it.
Anything else that might help me describe it to you, let me know.

[Regnier (gunrunner)]

FieroCDSP;

The Marlin Model 81-DL was made from 1941 to 1964. Since the barrel has only 5 lands and grooves, it is not a Micro-Groove barrel as there will be 16 lands and grooves in a Micro-Groove barrel in .22 caliber. That indicates that the Model 81-DL in question was made prior to 1954 as all .22 caliber Marlin rifles received the new, patented Micro-Grove rifling in 1954.
To get any closer to a date of manufacture, you might need to post a photograph so it can be compared to the Marlin catalog pictures of the era.