Conversation so far:
Who were the Kangaroos?
Heffernan debuted as "The Fabulous Kangaroos" on 3 May 1957.
What did Al Costello have to do with them?
Costello and Heffernan debuted as.
How did they perform?
Only weeks after that first match, The Kangaroos were working with the top tag teams in the promotion.

Question: How did things unfold after the promotion?
Self-contained rewrite: How did things unfold for The Fabulous Kangaroos during their first promotion?