This may be of help to everyone......sooner or later?
I was browsing through some grading questions, looking for a pricing list on World coins. I found something that may help identify slabs and their evolution.
Just go to www.sampleslabs.com. If you don't find what you are looking for there, you may get more ideas for research.
I hope this might help some. You must click on the grading company to the left to view all slabs.
Good Luck and Happy collecting!