There are several possiblities here for the headlight. Many of the early electric headlights were still square, especially those of the carbon arc variety. D&RG, RGS, Colorado Midland and others used those types from the early 1900's on. Another possiblity, is a conversion from an old oil headlight, which was also done, especially on the D&RG and RGS. RGS 40 and 42 carried their converted headlights into the 1940's, and one was put on 41 when it went to Knotts in the 1950's. All this from the RGS Story Vol. XII, to give credit where it is due.