The evidence shows that this plate scratch layout was used on one of the SC150/649 sheets. A few years ago using that information I was attempting to
figure out the layout of the other 649 sheet by matching up print flaws of the 649 subjects on this sheet like the Bransfield/Ewing in the above post.
I only worked on that for a brief period because I was still working on all of the other PD150 plate scratch sheets.
Here's what I have on the other 649 sheet so far
img822 - Copy.jpg
Yesterday I came across this JJ Clarke SC150/25 with a print flaw
Clarke.jpg
My first thought was when I saw was I wonder if there is a Ganley with the same mark being that he is a plate scratch match for Clarke and just a few Ganley's in my search I found this one
Ganley.jpg
So now I know this plate scratch layout was used on some of the SC150/25 sheets and it's possible it was used on some of the other sheets like the Sovereign 150's and SC150/30's which would present more possible cross references using print flaws to figure out the rest of the 2nd 649 sheet and possibly others.