I'm brand new to this site, which seems to be the only major road infrastructure forum going. I'm a Seattle resident with a personal interest in lighting and lamps, and I'll dive right into what I'm trying to find. As a young child, I noticed some warning lights, all over Seattle, and even in Renton where I grew up. My father pointed them out and liked to claim they were "warning critters" blinking at drivers. The common type has a pair of amber lenses, the lights behind which blink, under a half-round domed cover, and was mounted at the 'nose' of a street island or median. The ones I knew all got removed or quit working over the years.
As an adult, I ran across a working one, and then another, and another. I went out in 2005 and photographed all the ones I remembered, and examined a few up close. The covers are 75+ pounds of cast iron. The lamp boxes are steel, with two sockets inside; some I've looked into have been phenolic, others porcelain. The lamphouse mounts to, and the cover sits in, a back/baseplate (presumably also iron) which is set both into the asphant and onto the flat face of the island. There is no mechanism inside, and I suspect a nearby traffic signal control box contained a mechanical rotary flasher. I lifted a few and examined the inside. At that time, I knew of six working examples. Today, there are two (one a recent discovery, which no longer blinks). Three of the working ones I knew about have been completely removed. With some being part of Aurora/99, I'd hazard a guess that they're pre-WWII.
A friend suggested I use a phone app called Map Marker to ID all the known current and former locations; at this time, I know of 30 of these, including working, not working, and removed. Most in Seattle, two Renton, one Bellingham. I've been told the DOT calls them Mushrooms, and I have no idea what era they're from, or whether they were bought or built. Here's a photo of the one that still works properly, on the East side of Broadway at James.

I'm looking for anything about these. Known locations, current or former. Era. Whether they exist outside of Washington. Anything.
I'm also interested in anything regarding a few similar types. There used two be a plastic mushroom, which looked to me like insect eyes; I knew of one in West Seattle and one at the Sea-Tac Airport, both removed long ago. These may or may not have come with a flasher; the two lights in the airport one flashed independently, probably using "flasher buttons" in the sockets. I now know of a single-light version in Olympia. Then, Seattle has three (that I know of) single-light blinkers, an amber lens set into a concrete bullnose, as shown below:

Seattle also had a "wigwag" type, with two lights that flashed alternately, near the zoo. It has been removed. I've seen remnants of more of these under the viaduct, just north of Pike Place Market, though I never saw them working. The one by the zoo is shown below; the ones under the viaduct were just the rectangular plate that, in this case, was set into a bigger diamond. This one was red, but I don't know about the others.

I also know of a different sort, made by Crouse-Hinds, I suspect intended as an airport runway light. I know of two locations (on the same island) in Lewiston, Idaho which supposedly work, a few (some still there but not working, some removed) in Portland, Oregon, and reports from Salem. I've termed these "low profiles," and they also blink amber/orange.

I've found many old ads for a "mushroom traffic signal," but none show what Seattle has. They're all full domes. Someone told me Tacoma once had a full domre and sent me a blurry Street View shot of it, but that median has been rebuilt.
Can anyone assist?