All the 3pts I've looked at share a basic geometry in the way they work, but the actual dimensions are very different. Especially different in the way that the pins mount, the width of the mounts, and how much the arms and connecting pieces are bent so that the whole assembly ends up fitting the implement out at the ball ends. They are model specific......
The Kubota "Build It" site shows those 3pt parts kits as a $500 to $600 option for the L47 & M62. Just looking at the complexity and number of parts for our M59 3pt kit, I'd say that anything close to that price is a screaming good deal.