The best site out there for Louisiana cards belongs to a board member:
http://www.louisianacards.com/
There are more than 7-12 total T213-3 factory 8 OPs. I used to have a Hoblitzell and I think I came across examples of 2-4 more of that card when I owned it and was trying to figure out what to ask for it. PSA's pop report shows only 1 graded F8, Eddie Collins, but lists several others with 0 in the pop report (
https://www.psacard.com/pop/search/ then search "T213 Factory 8" ---- which I think means PSA confirmed them but has yet to grade one, not 100% sure about that logic, though it does make sense with the cards in this thread): Cobb bat off, which tbob mentions he had four (4!!!!!) of, Dubuc, Marquard, McGraw port, Bender no trees, and Jennings both hands. I also know someone with a blue Chase portrait. Combine all of these with what I know of the Hoblitzell and the Wheat, red Cobb, Merkle, and Donlin in this thread and quickly we pass the top end of your total pop range without doing more in-depth searches.
Here is my Tango Eggs card, I think you will like the back.
Very cool to hear that your grandfather hand a hand in these - I just sent you an email as I lived in New Orleans for 10 years and collect the cards from there.