Case SN gives us 1945, but mvmnt. has 49, giving 1949. Original band with "1/20 12K TOP" and "(R)" stamped on the inside. Only one correct hand, the minute hand, zero case wear and very minimal band wear. "SPENCER".http://www.mybulova.com/sites/default/files/vintage_ads/Bulova_AD_1946_4.jpg Light wear to numbers, but dial is good. So, how do you date a watch with a replaced movement?
We've been using the latter of the 2 Dates, which IMO is debateable.
When the Movement is dated within a Year +/- of the Case the latter of the 2 Dates works, in instances like this it does not as a Watch model manufactured / advertised as 1949 could differ from a model named the same produced / advertised in 1945.
a humdinger.
We're ID'ing the Case so in this instance I would vote to use 1945. - but that's just Me, others may view things differently.