I am interested in a Marlin .22 with a 20 inch barrel and gold trigger. The gun is 3 hours away. The owner says the rifle will not feed reliably if it is canted too much to one side.
I want to know if this is a common condition with Models 39, or is there probably something wrong with the rifle?

If it is indeed a 39M, there were only 500 made. As for the feed problem, no it isn't inherint but probably can be corrected with a good cleaning. The 39M carbine is the Mountie Presentation Model made only in 1960.

Here's a breakdown of Mountie/39M from marlinman93. http://www.marlinowners.com/board/viewtopic.php?t=20117
If it's reasonably priced, I would buy it. I guess you have to decide what 'reasonable' is. I have been looking for another one for a long time.