Wonderful WaJo related artifact, Ray! I'm guessing Boise was the only team in the league, also called the "Snake River Valley League," to be big enough to warrant having scorecards for their games. I don't think I've ever seen another. In my research on Walter's time at Weiser, linked below, I don't have any 2-0 or 2-2 games against Boise, but the scorecard owner might have remembered them differently than the actual scores.
http://cwcfamily.org/wj/ww0.htm