I’m afraid I don’t. I looked at them closely years ago in the days of the Smart magazine, but never understood how they were compiled.
The top rating is always 78, which doesn’t mean anything to me and the range/spread of ratings can be very close in handicaps, as you might expect. I don’t know if 1 ratings point = 1lb, as is the case with most other ratings methods.
The top-rated often coincided with the top-rated of other ratings based methods.
I found that backing the top-rated in non handicaps for 3yo and older horses on turf from April onwards was a fairly reliable system for anyone who doesn’t have much time to study form.
Sorry I couldn’t be more help.