Tanks for the Memory

Pickle's renewed interest in the military has taken another sinister turn backwards. His misunderstanding of the true situation has led him to make wild assumptions which (it is hoped) he is not passing on to his home planet because his superiors might think Earth is a 'push over'. While visiting the Richmond Fair he came across these antique tractors. Not having heard of Farmall tractors (neither have I, quite antique) he was heard to remark, "So this is what Earth tanks look like". Of course, he was mistaken, they are merely mechanical polo mounts, hence the knock-knees on the middle one!
LITTLE FLY in Codger's Caff/ You must think you are on staff/ For when I get up from my seat/ There's plenty left for you to eat!