James Bancroft, myself, and my husband rode the D&S excursion train today. Absolutely no sign of insulators for most of the line, only a dome of what looked like a CD 152 in the rocks along a tight cut at one point, and this old power piece that was on a pole with no sign of any other poles with a similar construction in the gorge that we could see. We were thinking it could have been an M-3740... not sure what else it could have been with the very flat top skirt and tiny wire groove. Any other thoughts?