Early Medieval Signet Ring?

Though its classification as exonumia is admittedly questionable, I'm not sure where else to put this. If anyone knows anything about it, can direct me to someone who does, or has even seen something like it, I'm all ears.
Twelve days ago, at the annual PNNA show, I found this broken signet ring in a dealer's junk box, so I bought it from him for $6. It is bronze, and appears to be early medieval, perhaps Anglo-Saxon or Germanic. It has (runic?) lettering around the circumference, and a very crude design. It appears that someone attempted to repair the band in more recent times. After a bit of research, I can't find anything like it. I've done my best to clearly reconstruct the design, but I'm sure I've missed some of the finer strokes in the letters. I have made a few impressions, but there's still some dirt lodged in the recesses, and I'm hesitant to do anything to it.







Thanks for taking a look.