I wish I had done this earlier. If I understand correctly these are Handlan buck D&RGW radial class lights on 340. In my earlier post I was wrong about how they work. I was going off of memory only. oops. BTW only one lamp has whats left of D&RGW, on a tag that is brazed on. all it says is D&R and a very ruffed up G.
MD Ramsey is this what your class lights look like?
Anyway, they work just as Earl described.
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Handlan Buck D&RGW radial lens class lights had both clear and green lenses. There is an internal shutter that is turned to blank off the undesired lens from showing in the dark. Earl"
The only thing he left out is when you rotate the inner shutter around to show the green lens and block the clear lens, you have to rotate the whole lamp to display the green lens forward. To do this you pull a spring loaded tab under the lamp then it will rotate in the bracket.
Here are some pics. This is the front with the clear lens forward.
This is the back of the lamp, displaying the green lens.
Here it is with the lid open. Also as MD Ramsey pointed out I did not know they cut the vent off thre top of some of these when converting to electric.
Here you can see the inner shutter covering the green lens.
This shows the green lens exposed after rotating the shutter. What ever was used to make the lens green is not holding up well.
This shows the bottom, with the handel to rotate the shutter. You push it up then turn it. You can also see the tab for releasing the lamp to rotate the lamp in its bracket.