Nice! My all-time favorite cobrahead too! They're getting hard to find here too though I know of a handful. All of them here are 100W MV but i guess they were used to a lesser extent in 175W MV too since Joe M had a couple with 175W lamps in them. They could have been 100W lights with 175W lamps but I don't think he would put the wrong wattage lamp in jut for the sake of it being incorrect.
Thanks! I think there's only around 3-4 of these left around here. I believe all of them got converted to HPS. Since this one lights a pretty big road I suppose it's either a 250w or 200w.
if this is MV, i'd guess it's 250W?