Quick notes following a conversation with Tony.
This is an idea for the Lilly & Jamaica story. All we have so far is the setting.
A timeline change occurs while L&J are asleep. They awake to find the world completely different but of course they accept the physical changes because their minds have readjusted without them having the opportunity to observe the change (!). They are alerted to the change, however, by a shielded devcie that records timeline alterations. Where before this device was electronic and whiz-bang, it is now retro-steampunk tech. It is still official DTJ equipment, and the agents recognise, understand, and trust it.
They return to 19th century to track down the time tampering nexus and interact with the DTJ offices operating there. Everything is steampunk technology. Clearly the change has occured much further back in history than this.