Here is a great example of a sign that was once red with only a hint remaining. The red has simply faded away.
I don't believe there ever were signs made with clear bells. And any such sign is simply a faded sign.

surb sign faded bell (2).jpg surb sign faded bell (3).jpg

Steve Coppens
Always interested in Sunoco items!
Really want a Sunoco National pump ad glass!!