JP Many of the watches came engraved, unengraved, diff gold color/content, dial color/configuration etc... We have ads for some of these choices, but for many we don't. In many or most instances, a different characteristic was indicated by a different variant letter designation, but not always. In most instances, the differences were noted by the unique Bulova model number. I say most, because we see some "unique" Bulova watch model numbers which remain the same, but the "choice" was indicated by a "W" or "Y" following the unique model number. For those with unique model numbers but different choices using the "W" or "Y" the model names appear to be the same if the Bulova model numbers are the same.
So to answer your question: IMO -sometimes.
I don't know if I'd call it an upgrade. Sometimes the price did go up, but other times an engraved vs unengraved price was the same. The model name usually didn't change, but a variant letter was often assigned. Often, not always. Bulova was inconsistent with all this. There are trends and patterns seen, but invariably there are exceptions to the pattens. If you printed out the Bulova model lists distributed a while back and just look through at model series or groups of model names/variants, you'll get a feel for the patterns and see the exceptions. The trick I'm finding is to look for the "exceptions" to help figure out the patterns, not the other way around....