Hi Frank, as a practical item the dish was very good,can be and could have been used for many things whereas the paperweight was either decorational or holding down paper. Can you imagine trying to put peanuts or pins or olives or olive stones or smarties or loose change or ash etc etc into a paperweight. I am surprised the decorative dish isn't or wasn't used much more.
As for whether the dishes of Perthshire on occasion were made from a slightly faulty weight only someone from the factory would know for sure I guess.
Perthshire, vasart, Deacons and maybe others have certainly made dishes as a first choice, and would certainly make a nice practical present for a friend.