Staining an old barn beam for mantel?

I have recovered an old barn beam, which may be alder, which I have cut to be my new mantel. The beams were found being dirty, so I have hand sanded much of the dirt away as well as some of the outer surface. Still, the surface is very weathered and rustic looking. I plan on staining the wood then sealing. I was given some partially used cans of stain made by Campbell and the product is Woodsong II. The back of the can says that I have to apply onto "new" wood. The wood that I would be working with is definitely not new, but very weathered. Can I still apply this stain? Any other suggestions?