Hi, and welcome to the forum. Before restoring that stove, consider the condition of the cast ion, any cracks?, shaker grate, lid missing?, clearance to combustibles for proper installation, chimney condition and size and the fact that it is not an air tight stove. I don't know if there is any parts available for this stove, but there maybe some that will fit. Look at http://www.woodmanspartsplus.com
for starters. Depending on replacement parts availability and the purpose of, or expected use of, or personal attachment of the stove and the money you to have to spend, would be your deciding factors.
I would look at another coal stove first. The burning of the air tight coal stoves are much longer. If a hand fired stove is what you want, there are a lot of great ones on the market. Since you are going from an automatic pellet stove, you may be disappointed. I would look into a stoker fired coal stove. You will be much happier. The cost is more and it also uses electric, so it won't work when the power is off, just like the pellet stove, unless you have back up power.
If you decide to restore the potbelly stove, take it completely apart, clean it up, and reassemble it with new fire cement. Replace any parts of course that are needed or in question. Give it a fresh coat of high heat stove black paint and it should look new. Since you are going to burn coal, don't forget to install a barometric draft regulator between the stove and the chimney connection. This will allow for a controllable fire and prevent over drafting or over heating of your stove.