I had the same dilemma a few years ago when I restored my own 100 year old hewn dovetail building. I ended up pressure washing the exterior and interior. This left me with a uniform color but somewhat fuzzy logs. I did nothing more on the exterior before applying an oil finish. On the interior where I didn't want the fuzz, I used a variable speed grinder with a grit impregnated nylon brush to remove the fuzz(made by Pferd or Osborne, available from Schroeder Log Home Supply - loghelp.com. I have only used the brush sander on milled timbers. I doubt it would work too well for you on aged logs.
Good luck.
