Good info, but just a little incomplete...
When I looked up the same info, when I was building some of my projects, it was easy to find the width of Cat1 attachments, and the pin sizes....
But one more important dimension for me was to know the center to center distance between the 3 pt arms and the top link pin...
The standard measurement for this is 18" on the attachment...... And can be as little as 15" if necessary.... I have not found any info that says this distance can be over 18" for any reason...
Good luck...