How are you so sure? I'm not trying to be offensive or anything, but you kind of lost your San Jose siren map years ago. We have suspicion there may be a siren located at those stations due to some mysterious control boxes laying around.
Because you could see divisions on the stator for the ports. So, I think it might just be a modified SD-10 similar to the one in this video. https://www.youtube.com/watch?v=dqkpY_Uw96k
Well, with more observation of this siren, it appears to be dual tone. It may be a modified SD-10 since if you look closely, it appears to have a visible dual tone stator.