This 6 coin 1942 "Wartime" Proof set has some very premium quality coins in it.
Low Mintage Set features the '42-P Type 2 "War" Nickel in 35% Silver, as well as the Type 1 made in the usual Copper/Nickel alloy.
Due to WW II this was the last year proof sets were made, until they reappeared in 1950.
This set also contains the last examples of the Proof Mercury Dime and Walking Liberty Half Dollar.
The mintage of the 1942 set is generally stated as being 21,120 as that is the mintage of the lowest coin minted (Half).
1942 was the last year you could buy Proof coins individually from the US Mint.
In a day and age where US Proof sets can have mintages in the MILLIONS, this set has only slightly more than 20 THOUSAND originally available.
Coins are as follows:
Lincoln Cent PCGS PR65RB Mintage 32,600
Jefferson Nickel Type 1 PCGS PR66 Mintage 29,600
Jefferson "War" Nickel Type 2 PCGS PR66 Mintage 27,600
Mercury Dime PCGS PR66 Mintage 22,329
Washington Quarter PCGS PR66 Mintage 21,123
Walking Liberty Half PCGS PR66 Mintage 21,120
https://www.pcgs.com/setregistry/alltimeset/158119