What makes them unique when compared to the rest of the Beacon Ray family is that instead of rotating 360 degrees, they oscillate back and fourth. It creates a longer "dwell time" at the end of each oscillation which is quite effective. They are less commonly found than the other Beacon Rays which also increases value. Used pieces in good condition with better tags and domes go for several hundred on ebay. Yours could use a new dome and a repro tag to help it display better. If it works, I think it would still fetch good money
One day, like when I win the lottery, I hope to buy one of these lights and add it to the collection. I've seen these on EBay for $500-$900. (I'd love an Aurora Borealis Mars light, too!) Hey...a guy can dream!
Here's a restored doo-dah that gives the whirligig the wherewithal to oscillate 95 degrees rather than turn 360. No pin on the driven gear = no 174. Dynamite light.