Stik: you can still complete your project for the 39/40 GB. It'll stay open until the 75th anniversary 1945 GB. I wanted to give anyone and everyone a chance to be in a GB for the whole anniversary of WWII.
So, you can do both--something for 39/40 and something for 41. I plan on opening up a 1942 GB on 1 January, 2017; a 1943 GB on 1 January, 2018, etc. All the GB's would then run till 31 December, 2020.