John, John McCullough built some mighty fine wood bows back in the early to mid 90's. It does look like osage, Is it rawhide backed? the condition sounds fine, if you want to seal the dinds just touch them up with your choice of clear coats after you sand them smoothe. Value is percieved but they are not made any more and you have a bow made by one of the best bowyers around.
I hope this helps.
Chuck