https://www.rugbyleagueproject.org/seasons/nswrfl-1983/round-21/balmain-tigers-vs-penrith-panthers/summary.html
At 45 second mark, there is a player for Balmain wearing number 19. You already correctly have numbers 15, 18 & 23. So either there was another replacement or someone replaced their jersey. Any Balmain people out there that can identify him?
https://www.youtube.com/watch?v=qQFI_XMvO2A