semi - that rifle looks like it was a dandy in its day. I'd say take the hardware off and soak it in some kerosene for a couple days then scrub the rust off it with a toothbrush. As for the barrel, maybe a bit of lapping with JB compound, a new nipple, and give her a try. Maybe a few rounds will get rid of that rust if its not too bad. I actually think she's stil a pretty girl.