Mike, I wish I could agree with this but I just can't. I know what Nagengast wrote about the 42-D but perhaps it was his writing that inspired others to go find the 42-D in the gem & premium gem grades. The population reports tell the story; the 42-D has a population of 368/1041 in MS65 and that doesn't include the full step examples which account for another 300-400 coins. You can get a 42-D in MS66 for about $50. I personally own 4 of these in grades ranging from MS66 to MS67 5FS. Here is my album coin. Given the population and Nagengast's comments, I would think that it would be very difficult indeed to find a raw gem 42-D, but there is nothing stopping anyone from buying a cheap graded gem and cracking it out.
tell me which Jefferson is tougher to find in gem, Paul. My assertion that the 42-D was the toughest to find in 66 and better. Which Jeff do you say is more difficult?
I like to split the Jefferson series into 3 parts: Pre-war (1938-1942), War (1942-1945), Post-war (1946-1964). IMO, you really can't compare the availability of coins across different categories. Within the pre-war category, the hardest Jefferson to find in premium gem is most certainly the 1939-S (especially with FS). After that I would rate the 1941-S the toughest. The others (including the 39-D and 42-D) are readily available in MS66. None of the war nickels are tough in MS66. For the post-war category, the 1954 & 1954-D are very challenging. I have been searching for a suitable example for each for years to no avail. And of course, all of the sixties Denver mint coins are an absolute PITA.