http://originaltrilogy.com/topic/Superman-1941/id/15907
The WB transfer may or may not have been done in HD. The anthology versions DVD and BD are identical to the standalone release, but the standalone release fixed a couple of the errors.
Which errors? It sounds like what we have now is the best we’re ever going to get.
There are actually a number of DVDs with PCM tracks but these are generally early on in the format’s lifespan as it was eventually decreed all DVDs would carry Dolby Digital.
I always assumed that was due to a space limitation.
A number of music related DVDs are PCM as well.
I do remember a few of those, I think those were if not common, at least not as hard to find.