Put the 51 feet tall 596 light deep blue Bromo-Seltzer bottle back atop the tower. Yes it caused massive structural problems to the building but you could see it for 20 miles in any direction at night, so, trade-offs really

Also it turned out that Bromo-Seltzer was kinda poisonous

put it where the sun sign used to be on the scoreboard

I mean you could probably fabricate a copy in a much lighter material.