Someone call for a Marlin nut??
Ok, the 989-M2, which was meant to be an M1-Carbine lookalike.
Yep, 2, not an R, is the same as a Model 70 or 995 or 989 with the addition of a wooden handguard.
Which is the predeccessor of the Marlin Model 795, the difference between those is the LSHO
(Last Shot Hold Open) feature & a bump in the magazine well that prevents Model 70 from being used.
So whatcha wanna do is use a Model 989-M2 manual.
The manual doesn't go very in-depth...but the FTE thread below has links
You can use Model 60 & 795 stocks if you decide to upgrade to a DIP Adjustable Trigger/guard kit.
But, those 989M2 walnut stocks were VERY nice...I've got one myself
A J&P spring Kit & replacement Buffer are the first things I usually change in an old Marlin.
Buffer from Marlin or brownell's/midway/Numrich...
Read my post on Model 60/795 FTE repairs here...