I found this roll searching. I knew as soon as I saw the date. It's the second one I found. I never found any other 1970's DDO. All the die markers are dead on. I went through 3/4 of a box finding nothing. Then there it was. I was so happy. Funny I posted on the roll hunting forum and only got 1 like and no replies. If it was MD I'd have 10 responses. http://doubleddie.com/452412.html
Okay, so you actually use the microscope to search? I use a 10x loupe and while I haven't found anything yet, sometimes I wonder if that's enough to find these.
I use it with my laptop. If you look at the 1970 ddo pics a lot of them are just a small bar under the 7 or the 72's a small extra bit on the 2, or 7. The minor ddo's are hard to spot. Sometimes I think there is something but It's almost always a light trick.