Lovely item, being an original handwritten letter and envelope, written by Sgt Virgil H. Warders. Looks to have been sent to 'Cecil and Merill Coleman' on the 5th May 1943, being written on Lowry Field stationary.
Warders was part of Bob Shoens crew (as depicted in Masters of the Air) and arrived at Thorpe Abbotts on 1 December 1943. They flew most of their missions on Our Gal Sal, one of the most famous B-17s to have been part of the 8th Air Force and her gunners were credited with confirmed kills.
There are a number of newspaper articles on the website of the 100th, with reports that Warders had been awarded his aerial gunner's wings around August 1943, that he'd completed his tour by 25 May 1944 and that he had been awarded the Distinguished Flying Cross.
The crew photo here is taken from the 100th Bomb Group Foundation website and shows Warders second from right.