W.S. Darley Sirens

Champion
The Darley Champion is a large dual-ended siren with two sets of choppers. You can identify it by the trapizoid-shaped base and "CHAMPION" written on both sides. It shares a similar design to Sentry's Model M, only without the "pipes" on the top and being overall larger.
Sample video: https://www.youtube.com/watch?v=RMfwkPgdVKo

Weatherproof Champion
Probably one of the more unique members in the range in that it has built-in slots and resembles a fire hydrant without the "arms" and "hat". There's basically two versions that can be found, but are largely the same.
Sample video: https://www.youtube.com/watch?v=Q_ewbj8DX7A

STH-10
The easiest of the group to recognize in the wild (assuming you can find one) as they share a similar appearance to Federal Signal's STH-10 except the horns are recessed into the body, but not completely.
Sample video: https://www.youtube.com/watch?v=W4knBhwEAIg

Champion Giant
Not to be confused with the regular Champion as this siren is actually vertical with a rainshield on top, 1 louvre/skirt underneath and three support legs.
Sample video: https://www.youtube.com/watch?v=j9J8Z3Rkn9I

Model 2
Largely similar to Federal Signal's Model 5 and 7, it's mostly with a more rounded top and skirt underneath. Definitely resembles that fire hydrant look the company is known for.
Sample video: https://www.youtube.com/watch?v=r6UNVjMhK9I