Yep, Brock is correct, April 25, second game.
I prefer to use Retrosheet when I date my more than 4,500 scorecards, that's where Baseball Reference gets their info.
In this case, the quickest way is to see how many games Grim pitched in Philly that year, and you find that there is only one :
http://www.retrosheet.org/boxesetc/1...252PHA1954.htm
Not sure what 11146 is, maybe it's the lucky number, the attendance that day is listed as 19930