[Domer05]

That's a reasonable description, Greg. Trench made that pennant; and, they made a 1960 and 1961 photo pennant using the same "LOS / ANGELES" script with team photos bearing 1960 or '61 dates--all shot at the Coliseum. So, the story checks out. See below pennant. (source: Doug Goodman's spectacular collection.)

...But, if it was purchased at the ballpark in 1958, it didn't come from Dodger Stadium; rather, the Los Angeles Memorial Coliseum where they played in those early days.