Interesting pix. I didn't know Yanmar ever used the combination of that better air cleaner with the rear-hinged hood. Maybe you have the later series engine installed? Does the engine tag say 2TR20A-X?
Also, I see the same mount for the loader's controls as my YM240 and I think the same control valve (AICO?) but with an added hydraulic filter, while mine has nothing but the screen inside the transmission. Update - I looked over in your other thread and see you have a front-mount hydraulic pump with the loader's hydraulics separate from the tractor's. That's a better design and the loader probably operates a lot faster than one driven by the tractor's hydraulics.
I think you are going to need the sway chains that should go from those rear arms, over to the mounting points at the ends of the axle housings.
And finally, if those wide tires still aren't sufficient to avoid bogging down I think it would be a great idea to have axle extenders fabricated, to run duals. It would be unstoppable.