Some of that is due to a much smaller mintage and die polishing. The mintage for the 1936 Proof half was 3,901. For the 1941 half it was 15,412. They pushed more coins out of the 1941 dies than they did the 1936 dies. That results in a loss of detail after a while if the dies are not replaced. Collectors complained about the lack of luster on the early 1936 Proof coins, so the mint polished the dies with a resulting loss of detail. On the later issues, they polished more after they had been already struck a fair number of coins. There are 1941 Proof haves without the designer's initials as a result. I've seen 1942 Proof haves that looked like Ms. Liberty has has had her hand amputated and cents that had Lincoln's bowtie hanging in mid air.
Thanks for the thorough feedback. All of the subject coins seem to have white spots that look like voids in a coating process. Is there an explanation for this?
I think @johnmilton nailed it when he noted that they had been dipped somewhere over the years. Looking closely at them they appear to be droplets that were not thoroughly rinsed when the dipping took place. That’s my gut feel anyway.
I tried to take a couple of photos through a lighted magnifier. My gut tells me the white spots are remnants of some attempt at dipping that weren’t properly rinsed. I may very well be wrong but I certainly get the feel of dried droplets.
I couldn't really tell if the plastic case they are housed in was sealed, or the type that you open to access the coins. If it is a sealed set, I would think that dipping would be out of the question and maybe the spots were caused by poorly washed and dried planchettes.
These coins were originally shipped from the mint in something like this. They were in celluoid sleeves.
It's a Whitman mint set holder...just pry the two halves apart and dump them out. Oh...you're right just the 4 screws...even easier!