First off, don't plan on anything till you shoot a few different loads thru it. I've heard of more than one gun with horrid bores that still shot surprisingly well.
But don't get did of it. Yes, rebarreling is an option and IMO I'd get it done in a heart beat. Sleeving it is another option to keep the gun more original. Baring anything else it was grandpa's, hang it on the wall if you don't want to mess with it. DEFINITELY DON'T part it out. Someone will want it as is.