Hey

I am planning on using a heart pine beam from an 1880s house floor joist for a fireplace mantel. It will have to be cut to size, so the ends will have a fresh cut. I will probably make the cuts with a chainsaw to give it that kind of rustic look, but I was wondering what I could do to it to give it a similar look to the rest of the beam. Also, should the entire beam be treated with anything to preserve it? I have heard tung oil mentioned. The beam has saw marks on it from when it was cut. I would like to leave them and bring them out even more if I could. Anything I can use to do this?

Thanks