Bought for scrap value so was the second one
Got both of these from a full time jewlery trader on his day off.
Amerindian site doesn’t quite match either mark and I don’t have a Hogarth 5th yet as I’m such a rookie.
I just checked BillieHogarths web page sadly at the moment they do not ship internationaly
Hi @LiquidGold, I’m in Canada and have the same problem as you: the Bille Hougart site does not ship internationally and therefore I cannot obtain the 5th and final edition of his Native American and Southwestern Silver Hallmarks 
Out of desperation I finally bought a 4th edition that I found on eBay. It was expensive, but also the only choice available to me; so in a pinch you might try that. You can get it via eBay UK, too, it’s just that the shipping is rather pricey.
I do hope that someday the Hougart estate makes an electronic copy of the 5th edition available, but I am not holding my breath.
Anyway…
I checked the 4th edition and there is no one listed with the initials GJ (your second ring), so that’s that.
Your first ring has a mark that looks to me like a JA, wouldn’t you say? Hougart 4th lists a Juan Abeyta (Navajo) whose marks are either J A or J. ABEYTA, but only the latter mark is shown; and as the J in that mark doesn’t have a stroke to the top of the J as yours does, I think it is unlikely to be him. Juan Alberta (Navajo) also has J A but no examples are shown. The other “JAs” in the book look distinctly different to yours. So I’m afraid that’s rather inconclusive.
In general, Native American silversmiths have preferred to stamp their pieces with ‘Sterling’ rather than '925’, so the presence of ‘925’ may suggest that a piece is Anglo or made elsewhere (e.g. the Philippines). That said, there are exceptions, so it is impossible to be sure.
Hopefully someone else with Hougart 5th edition will chip in if they can shed any more light on the question!
Thank you so much for your kind help @chamekke and assistance looking up hallmarks and advice to track down Mr Hogarths’ book.
It appears the bear traps are moribund and I can only learn by experience. It’s beginning to dawn on me that buying real NA jewellery is going to be much more complex in the UK than I thought.
In the UK there is no legal protection for declaring pieces as made by true NA silversmiths in the same way they have in America. I have come across many new pieces with turquoise and coral that experienced traders claim are real described as NA and not even the word “style” after that.
If anyone has time for a big project that needs to change here.
