I agree on the single folk wheel. The other issue with the rear wheel, how does it turn, with brackets on the outside of the wheel? I think you could rotate the wheels from behind to underneath and then rebuild the trapezoid frame work to have the forks sit level. Since it's not carrying weight, I would separate the wheels and add a post in the middle so you could turn the jack. Then cause I don't understand how does the jack raise on a spring action and not a hydraulic jack? You could fashion a hydraulic jack and add the lever. At least that's what I think I would do with my pallet jack.
I think Frenchy's options are better for a more realist pallet jack. The Plus model looks to be for European pallets and J Model for American pallets from what I can see with the fork spacing but I could be and probably am wrong with that.