I looked at the 3 point on my B7100- the bottom mount system is similar, but the rod that runs through is wider, so the base of the lift arms is wider. Therefore, it doesn't need the bend in the arms. If you can't find original equipment or something aftermarket that mimics it, you can probably get the components for a B7100 or the like and install that, with the straight arms. I will pm you the link to my website- it has a photo of the base of my 3 point, for comparison.
Kubota made a lot of variations, but they seem to be adaptable. I deal with 3 point systems a lot, so if I can be of more help, I am glad to. It is educational for me, too.