From what I can see from the pictures, if it is a reblue, it is very well done. There does not appear to be a softening of the metal, the sideplate fit still looks good, cannot discern any rollover on the edge. Have you checked for a date stamp on the frame? Smith also put reblue stamps on guns in the past, wonder if it has one? How about some good pictures of the left side of the grip frame with out the stocks?
By the way, reblue or not, you hot a great deal on that 29!