Over the course of the story, it's mentioned several times that Corbin's back has a tendency for unsavoury cracking noises, and he's obviously in pain ever again. Makes a lot of sence once we know that Corbin was a child labourer as soon as he could walk; no one in Victorian England took the physical health of underage factory workers seriously.
Corbin's cribbage set is held together by a ribbon that reminds Lauchlan of a hair tie. Considering what we get to know later and Corbin's emotional reaction upon getting the cribbage set back, it's likely that it's a hair ribbon of his deceased sister Eloise.
