It looks like a modern JB that someone, (other than the factory), installed the cover. Hard to believe that the factory would do that sloppy of a soldering job.
There's another thread also where member HSB (I believe, or maybe Eclecticsynergy?) laid out a bunch of information about base plate and label changes and approximating years. You might be able to get it down to a 4-year range if you find that thread.