The Walton Powell is a very nice rod ~~ and 8'6" is not a bad length. You can get more information at the Classic Fly Rod Forum ~~ there is a section there to post looking for more information on makers. Cherish the rod ~~ but more than that cherish your father who shared a little legacy with you.
I forgot to add a couple of things...
Do not sell the rod until you know its full value (the Classic Fly Rod Forum will help you there)...
And make sure the rod is bamboo ~~ Walton Powell was one of the first to develop the Hexagraph rod ~~ a graphite rod made to look and cast like bamboo.