1942 - J.A.K.E. suffers massive damage fighting a T-Rex on Dinosaur Island. He is rebuilt as J.A.K.E. 2, now with internal weapons.
1945 - J.A.K.E. 2 & the Creature Commandos join the final push into Berlin. they discover Vandal Savage's attempt to clone a new body for Hitler, initiating the Secret War.
1947 - J.A.K.E. 2 is destroyed while fighting to destroy Hitler's Brain.
G.I. Robot was featured in the 60's era Star Spangled War Stories. He's a little gem of a character that's trotted out occasionally and always comes across fantastic, because he's just the best. He's had several versions that have cropped up over the years, but the idea of him fighting dinosaurs on a lost island in the pacific goes all the way back to his first appearances.
His association with the Creature Commandos actually didn't crop up into continuity until much later, and I don't know if he's ever actually been named a member of the team, but it's pretty much a no brainer to fit him in with them. There's a purity of concept at play here that is just way too much fun not to use.