This one I found on the internet as well. It is far from being home-made. Apparently it is available in the UK.
It has a very slick look. I guess we have to give them on the other side of the pond credit for "thinking outside the box".
I like your idea of using the job box Stagelines.
I wasn't really sure where else to post these ballasts that I found on the internet. This first one I found on another website. I forget where I found them, therefore I can't give credit to anyone who designed them.
I know there are a few of you out there that have the discontinued freedom hitch.
I have a mount for the three point and one for the implement that I would be willing to sell.
Let me know if any of you have interest.