Anyway does anyone know when leatherman made the change between the two fixing types?
You got it the other way around. Only the first ones that came out had torx, and the second batch a few months later had rivets. From then on all of them have rivets.
...........I think leatherman and the others are missing a trick by not making a side cutter folding tool. I use side cutters at work a great deal more than pliers and for cable ties nothing else is really safe to use right up against wiring. I know someone on this forum has done a very good mod by adding cide cutter jaws to a sog but it shouldn't have to be a mod, anyone else see the need and wish the big names made such a thing?