This siren's motor cover and projector, unless they were painted some really dark color, look rusty, and the Penetrator's fiberglass don't rust. It looks somewhat like the siren in this post:
murrfarms wrote:
That's quite possibly a Mars-branded siren, which was basically designed after the Federal Type B. They just used a different mounting base for the motor and a little different sheet metal work, but as best I can tell the mechanical parts of the Mars siren are the same as a Federal B.
It could also be a single headed Sterling. Just a few guesses.