Addendum to my post. 1956 was the year an adjustable saddle was offered as an option. Tone and volume suffered as a result. Another thing worth mentioning is the bridge plates on '60's models; the earlier and smaller design of solid maple plate was discarded in preference for a huge laminated plate. The idea was to try and improve stability whilst still using light materials.
The problem was that the laminates didn't have the tensile strength of the solid wood and many de-laminated themselves rather than flexing with the top. Again, avoid. Good 45's and 50's aren't exactly rare so finding a great example shouldn't be that hard.
Good luck and have fun in your search.