It's an old permit so presumably the work has been completed. This could have been something as small as a couple walls back stage so not necessarily something guests would notice.
Hmm, so they had the imagineers do it? That's quite a change of pace. Usually they hire a construction company. I'm sure the imagineers were not too happy about having to do manual labor. The young ones likely muddled through it just fine, but I'm sure it took a real toll on the older guys.