Hey Steve,
I see the post has quite a few looks but no responses yet. I am a little confused so others might be too. The "rising sun" piece is not glass but a separate chrome plated metal insert in front of a piece of generic frosted ad glass. I'm pretty sure generic pumps would have been shipped with these standard, as all the period advertisements I've seen for 60's show unbranded examples with these in place as it was part of the original beautiful design.
I would assume pumps ordered brand specific were either shipped with the brand's ad glass, or the rising sun design insert and frosted ad glass was switched out after they were delivered to the station. I have no knowledge of that specifically, maybe Jack Sim would. I would also assume Jack may also know if the pump repair manuals give this part a specific name as well.

Darin Sheffer
Always looking for Mobil and Marathon items I don't already have!