Evan,
Depending on your soil, that plow will probably be fine. I would try it as is before you change out the share and shin, unless they are worn in to the frog (the cast part to which they are bolted). But, you need to work on the moldboard, if you want the plow to scour (keep the soil from sticking to it). Sand off as much of the rust as you can without removing too much of the steel. Once you get it to scour, the soil will clean up the rest. Then, when you are finished using it, protect the moldboard until next year with a coat of grease, or a coat of some old paint you have lying around.