OK. I have a 2009 Kubota
M6040. Just went out and looked. #1 - you are absolutely correct - a picture isn't going to tell you squat. Your description doesn't seem to match what I can see on mine. Suggestion - modify your bio and list the year of your tractor.
I crammed my head up into the side of the engine compartment and this is what mine has. There are two open "U"'s attached to the engine bulkhead. One on each side of the bulkhead. There is a shaped piece of flatiron attached to the back underside of the hood - one on each side. These flat irons angles down and terminates inside the "U"'s. I can not see how they are held inside the "U"'s - but I would guess some kind of pin.
I would imagine that what you are looking for will be the same on all M**40series. Meaning -
M5040,
M6040,
M7040, M8540, M9540.
You are looking for the proverbial needle in the haystack. Somebody who has taken off & reinstalled their hood - on an M series Kubota.
Suggest you contact the service department at your local Kubota dealership for clues, hints, tips, suggestions.