"But problem is, can't really do that." Why not?
I never actually see them replacing streetlights, only see it done after. Closest has been where I thought they might be replacing some but they hadn't started.
Also tried to contact my Co-op where I live about getting old Powr/Brackets or AEL ballast in arm, but was just told they scrap them out. They made it sound as if they weren't worth messing with. So I wasn't able to get any access unfortunately.