[bk400]

Does anyone know which was issued first?

The 54 Topps was in the third series, so I'm assuming that it was issued later in the year -- or at least later than the first two series.

The only relevant information I could find about the 54 Johnston Cookies is that Aaron's card was issued when he replaced Bobby Thomson in the Braves lineup, after Thomson broke his ankle on March 13, 1954. Bobby Thomson's Johnston card was pulled and replaced with that of Hank Aaron.