A while ago I found (and recently bought) what could well be mistaken for Peter's royal signet ring:

https://www.ebay.com/itm/121657454515

The shield design is roughly similar to that in the movie: a lion rampant in front of a stylized, symmetrical tree. Of course, it's not licensed Narnia merch, and the creature on it is labeled as a "wolf" but it definitely looks more like a lion. The shape and design are pretty clearly taken from the movie shield imo. The leaves along the band also look very Narnian inspired, not unlike the kids' crowns.

Pairs great with my knockoff Peter's Armour Hoodie!  

@the-mad-poet That's very definitely a lion and it does seem to say so on the site — maybe they changed the wording? Looks fantastic and a great buy  

@courtenay Why so it does! I had it on my watch list for several months and got used to seeing it labelled a wolf  

@the-mad-poet Maybe someone pointed out to them that wolves don't have such long manes and tails...   (It's actually pretty similar to the lion on the Royal Standard of Scotland — or the Peugeot car badge, for that matter.)

It's a really nice ring and I wouldn't mind one like that myself, if only they had a girls' version! Mind you, eBay tells me this particular company doesn't ship to the UK anyway.

It comes in a variety of sizes, so a girl could possibly get away with it! (I mean, I get that it's geared toward guys what with the "biker"theme, etc.) That said, I got a size 13 just to be safe since I have relatively thick fingers and have had trouble finding big enough rings in the past... only to find out that it's a trifle large on me. It still fits fairly snugly on my third (towards the end of the day after it's had a chance to swell) but I wouldn't risk swinging my hand with it on for fear of sending it flying . Either they run large or my hands run small, I guess. 

I had to look up the Peugeot car badge...I must say I like the look of it, especially the older ones!

I do have the Scottish royal standard in my flag collection and I must agree, the ring matches it quite well. Might consider for a Robert Bruce cosplay sometime...

That's unfortunate that it won't ship to the UK! Mind you, I found many very similar lion-themed signet rings out there both on eBay and Amazon (to say nothing of Etsy), so it might not be impossible to get something like this.