Because the 989 is a magazine fed rifle, the 22 short may not feed properly. In addition, if you fire many shorts in the rifle you run the risk of building up dirt that will attract moisture and cause corrosion. If the chamber gets corroded at the front it will not feed 22 long rifles well. If you must shoot sorts, clean the chamber well when you are done.
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 .
Try e-gunparts.com
Contact Marlin customer service through their website, and request an owner's manual for your rifle. They are free.
50-125 USD
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.
I'm not sure what they are worth now, but I bought one a few years back for around a hundred bucks..
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.
Try gun shops, gun shows, pawn shops, estate sales, garage sales, want ad, for sale ad, egunparts.
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.
try Numrich Gun Parts Corp.If they do not have one,maybe Marlin itself may have a few still in stock.E-bay would be another good place to find a stock for your rifle.