I received a heads up from another Brian (thanks!) about this great website
www.sportingoregon.com which was noted before on this forum but is worth checking out for all the cool photos and cards of Portland baseball. It shows all 12 Portland D310 cards, and includes images of Chadbourne in both Green and Gray tints. This info, along with yomass's (Richard?) list of cards posted below
Steen, Portland
Murray, Portland
Hoffman, Oakland
Tiedman, Oakland
Wolverton, Oakland
Danzig, Sacramento
Berry, Sacramento (This should be San Francisco)
Sutor, Sacramento (This should be San Francisco)
that he has in both tints (all of which are players on my original gray only list), as well as Leon's green Ryan as shown in a previous post and Mark M's Mohler, that my evolving theory can be stated as such:
The D310's were probably printed in sheets of 24, probably in different runs, all cards can be found in green, and only the 24 cards listed in the original post can be found in gray.
Now the challenge is to show us one of those 24 gray only cards with a green tint so that a hole can be blown clean through my high falutin' theories.
Brian