Paul, that looks like the read out I get when I test silver or what might be silver. So I am guessing that is my picture from the past. Bottom line I guess unless someone is willing to destroy one of their Hilton Sets so it can be tested and weighed it is only a rough guess as to exact weights.
Here is a scan of the different brass ring weights I have come across over the years. I work here and there for a couple different coin stores and am asked to pop out the silver inserts to be melted. I keep the brass rings and for fun I weight them.