Thanks to WAX6428 for finding this location!
I've been closed minded enough to be searching as Marston for the most part, and would never have found this most likely.
#14 In the cabin of the sunken boat, Van Horn Credit to WAX6428
Here's the screenshot album: https://imgur.com/a/yw8LAX6
Know of any others? Fancy helping me find the rest? Thanks.
So, to summarise there's:
8 Newspaper Cheat Codes
27 Found Locations
2 Unknown Locations?
These many locations in each State:
Ambarino 7
Lemoyne 5
New Hanover 6
West Elizabeth 3
New Austin 6
#26 You want something new
#32 You want freedom
So close, only 2 more remaining!