Counting home games here
http://www.baseball-reference.com/te...e-scores.shtml
I come up with July 15, which was a Dizzy dean shutout during a sunday doubleheader. So a mistake over which double header it was seems likely.
But there's the odd day off on Monday the 16th, followed by The cards again on the 17th and 18th.
Any chance at all that there was a rainout earlier in the season pushing game 32 to the 16th which got rained out and replayed on the 21st? It seems unlikely considering the way ties and rainouts were handled at the time, but might be worth a bit of checking into.
Really neat items either way.