1902 Coronation Coin-Necklace

Hi all, hoping some of the experts here can help on this, found in my grandfather's estate; as trustee I need to establish if it has any notable value.
I've found lots of things online a bit like it, but nothing quite right. It's about 20mm including the surround, 18mm inner. Both faces are coated in slightly domed glass (you can see my greasy partial fingerprint in one of the images).
The surround is stamped "BGCO 9CT rLD" and appears to be copper, so perhaps was gold plated?
It was stored in a red card box, with a crown and "BGC London" printed in black on it.
Alexandra is facing left (which I can't find in images or mentions anywhere), and the date is the cancelled-through-illness date originally planned for the coronation - I've read the majority of memorabilia has this incorrect date.
I'm note expecting any great value, but having gone coin-eyed staring at google images for a couple of hours I'd be grateful if anyone could put me out of my misery!