Bill,
I buy a used hammer double or two every year. I look for good, solid shooters. I will and do look at refurbished guns BUT, I give them even closer scruteny than ones that have no indication of having been refurbished. Reason is simple -- some refurbishing makes the gun less safe as a shooter -- too much reaming of bores to remove pits, lengthing chambers, removing dents, poor "repairs" to locking lugs, hinge pins, etc. Some refurbished and/or repaired guns get a solid approval because the work was done well -- I am considering one such gun now, one made in 1890.
I have also seen guns with really poorly done repairs, so poorly as to decrease the margin of safety, or so inapproprate to the gun as to make it undesirable to me (such as recutting net checkering to diamond checkering). Guns with case hardening redone are avoided entirely, mostly because I don't like case colors and partly because I don't want to take the time to assess possible warping or loss of strength caused by inapproprate recasing.
Niklas
