Posted By:
runscottIt's easy enough to find the data, but I'm looking for a "collaborator" who has familiarity with the "Players' League vs National League" intricacies, rather than the data. I haven't read the Spalding or Reach Guides from 1891, but I assume they would have some interesting narrative, especially the Spalding Guide since Al Spalding was associated with it. I have read the 1891 Sporting Life Guide (the only year it was published), and it has fascinating insight - unfortunately (stupidly), I sold a reading copy to a wealthy collector who promptly locked it up in a vault. 
Any help is appreciated, and the end goal of this is an article, which I don't in the least mind sharing a by-line with the as-yet-undiscovered collaborator.