[RAM1961]

Hi, a friend brought over a Marlin 80 DL with tube feed. It's missing a peep site on the rear and I think it's missing some kind of mechanism in action to feed shell up to bolt? There's nothing in there at all. I can't find anything on it googling - any ideas what I need and where to get it?

EDIT: It's a Model 81DL

Thanks in advance.