OK . . . the answers to questions number 1 and 2 (probably the rest, too) can be found right here, on our very own JWMB.
I will answer question #2 - Stagecoach, The Fighting Seabees, and Overland Stage Raiders.
Great job, Keith, on a fun and challenging game!!
At least according to IMDB, El Dorado and True Grit do not share any filming locations.
In looking at images from El Dorado, I couldn't find any place that looked like the picture above, so I am thinking probably the answers for question number 2 are not correct. True Grit was shot mostly in Colorado, and the CA locations don't look like the above pic, either.
