I have a Bulova 23, 1956-1959 based on the 10 BPAC movement, unremarkable except for one thing. Under the words 23 Jewels on the upper part of the face is the word REBUILT. It is stamped on in the same manner as all of the other wording. Any insight into this? I've been asking around for years at jewelry shops but only get shrugged shoulders. Thanks.