Went looking around at a couple flea markets today and spent a total of $3 for a few odds and ends. The thing I was most excited about was a hammer head I found hiding behind a barrel of shovels. It was rusted up and cost me $1. Brought it home, took a wire brush to it, and treated it with linseed oil. I would have liked to make my own handle but my shop is in the beginning stages and I dont have the tools yet so i ordered one.

My question is; the hammer faces are just a little rounded from use. I was thinking of taking a belt sander to it to flatten them out but wanted to see if that was a good idea or not. I dont want to mess anything up. Any tips?

Oh, it weighs in a 2 lbs 7 3/4 oz.

I'm thinking keep the profiles that are there for now and if you need something different it's easy to modify later.  Depending on how nicked or dinged the faces are they may or may not need a little cleanup.   My hammer that is similar has one face slightly rounded,  think the face of a pocket watch and the other is flat with nicely radiused corners for making tapers nice and flat.

I would agree with using it first, then modify if needed. If you are going to flatten it, I would say just do one face and leave the other rounded to leave you options.

Been looking at info about dressing hammers, now that I know that's a thing. I need to update my description to be more clear, the edges are a little rounded, which seems to be a good thing, but that wasn't what I was actually trying to get at. One side specifically, the top of the face is longer than the bottom so the face slants a little. It is a "round" slant but it looks like someone had been pounding on the bottom of the face mostly instead of hitting flat. 

I'm thinking that needs to be brought back to flat and then dress the whole thing to make sure I dont have sharp edges. 

I was reading about the "wood test" to see if you are hitting flat but I think hitting flat with that side would leave a 12 o'clock indention, if I am making sense here.