On the main Marlin Firearms website, there is a section labeled "Owners Manuals", from which you can download the manuals of Marlin products in .pdf form. Assembly and disassembly instructions should be included in these manuals. See related link.
Your Marlin model 989 which was a semi auto promotional model will range in price from 75-150 dollar,depending on overall condition.
try eBay that might do .
Contact Marlin customer service through their website, and request an owner's manual for your rifle. They are free.
Marlin 336 Owners Manual at Marlin Firearms website: http://www.marlinfirearms.com/pdfs/manuals/MFC_Centerfire.pdf
I'm not sure what they are worth now, but I bought one a few years back for around a hundred bucks..
I have one that I'm sure I bought in about 1967, I think. I bought mine in 1964 at a Woolco store in Tempe,AZ. AnswerThe 989 (standard model) was made from 1962-1966 The 989M2 (M1-Carbine lookalike) was made from 1966-1979.
The marlin model 39A is the rifle model,while the Marlin model 39M is the carbine model.
Try a thorough cleaning, change magazines, change ammunition. The marlin 989 was made in the 60's the bolt does not open when the last shot is fired
I have used the 10-round magazine for the Marlin 795 sold by Brownells (www.brownells.com) as 550-000-337. This is a nickel plated mag. Aside from extra capacity and nickel plating it appears to be the same design as the 7-round magazine that came with the rifle (Marlin 989). Brownells also sells a 7-round blued mag as 550-707-346 that should work.