Switchstand lanterns *LINK* *PIC*

The thread on vintage Alamosa reminded me of something I have been curious about...
In reviewing photos of the D&RGW narrow gauge it appears switch stand lanterns were still in use in the 1960’s as evidenced by the photo below taken by John West in the Alamosa yard in July of 1963. Other photos in John’s Memories Albums (see link) also show lanterns in Chama around this same time period (I think he also had one photo posted at one time with an illuminated lantern but then again I may be imagining it LOL).
So several questions: when was the practice or operating dept. requirement to have illuminated lanterns on switch stands ended? Was this an AAR practice that other RR’s also followed?
I assume that the task of maintaining these lanterns (wicks/ kerosene) would have fallen to the section men in whose section the lanterns were installed. Were certain turnout locations mainline vs. yard designated that a lantern, and /or colored target (which shape of target (round vs. diamond) and color code red or yellow) were to be used? The D&RGW standard switch stand specification sheet for Style 112D (6 foot tall stand) dated May 29, 1954 shows a red 2 sided 18" diameter target but still specifying a lantern tip on the top of the shaft.
I have no doubt that switch stand lanterns were an easy "target" for thieves as their collectible value increased. But at the same time it would seem an illuminated lantern given the night operations conducted right up to the end of operations in 1968 would be an important safety factor for crews.
Rod Jensen