Check out the scoreboard... a barn, tanks, trains, trucks, cover missions, escort missions, sweeps, strafing missions, and I bet that huge bomb means a special mission
He participated in every major campaign on the Western Front, including the invasion of France on June 6, 1944, the breakout from Normandy, the Ardennes, and the Battle of The Bulge.
His brother, Walt, was a B 25 tail gunner on Betty's Dream http://www.warbirdradio.com/tag/herb-stachler/
You can read quite a bit from his recollections of his time in the war at
For Comrade and Country: Oral Histories of World War II Veterans edited by Robert G. Thobaben, a book that you can read some of on Google books
I looked around online for over an hour, and no one seems to have just written down the accounts of what his missions were, what the barn was, or the big bomb symbol. Damn, didn't anyone ever ask him?