House System closer look.....

[The Dark]

All of the WWI vehicles I've worked on were done using FF&S, although I use a couple shortcuts (I use the vehicles' recorded speeds rather than calculating them, as an example). The American Civil War portion uses WTH as well, since FF&S on its own doesn't cover black powder.

For adding dinosaurs, the core TNE rulebook will probably be the most useful, since it has the rules for creating aliens.