This PCGS file tells you a lot of what you need to know about the very early coins from the 1930s, but there is really very little I could find about other Washington quarters, notably those from the Forties through the Sixties before the switch to clad. PCGS points to the oddities, the irregular strikes and so on in this discussion of theirs too much to suit me. There is a wave of the hand at one early 1940s coin here, too, but as with the others discussed, the main point is the odd coins, and not necessarily those that have lower mintages. https://www.pcgs.com/resources/guides/Washington_Quarter-web.pdf EBay sellers seem to think that there are lots of key date GWQs. I counted 22 different dates and mint marks called key dates in a search of their listed items, ranging from a '42-S to a 64-P. I could not find much to substantiate these claims for a key date status. I did check my records to find that I paid more for a '49-D than any others from the 1940s, yet that one didn't make it into any of the listings as a key date. So, in your educated opinion, what are the key date GWQs? If you have pictures, please share them. Thanks.