Here's a pic of some GE M400A3s on I-190 at the south end of the South Grand Island Bridge near Tonawanda. You could see the start of the Holophane lights in the background of the pic.
I remember when there were clamshells on the Grand Ilse Bridge. If you look closely, the cobra heads were attached to the upper end of the existing ole.
The davits are not original. They were attatched to the existing uprights in 1991 when both bridges were refitted with Holophane HPS luminaires. The original truss arms on both the South and North GI Bridges had a good variety of old MV luminaires. The North GI bridge had OV-20s as the original installation, the South had Form 400s.