How might I be able to date the age of a vintage Coca-Cola sign?

I recently gifted my Grandparents a seemingly vintage Coca-Cola sign. It’s a box light used for advertisment (as to say, it’s a neon light inside a shimmering box of colored plastics).

The sign is tagged by what looks to be a relativly generic lighting company, with no real regard to it’s history.

Don’t get me wrong- I watch my fair share of Antiques Roadshow, although I’m at a loss as to how to find out this particular spot of info. Can the Dopers help?

Oh, one more clue… the ‘slogan’ emblazed by the lighted insides is “Enjoy”.

Thanks.

The quote is from this website; IANACollector of such things, so take it with a grain of salt.