Hanging two of my grandfather's paintings

I'm in the process of figuring out how best to hang these paintings. <%popup(20070124-painting1.jpg|800|617|Here)%> and <%popup(20070124-painting2.jpg|380|600|here.)%> They're oil on wood. I'm thinking of attaching 3/4" wood border around the back, flush with the edges, so that when it hangs, the border will be flush with the wall. It'll also give some reinforcement to the larger painting, which is quite flimsy.