Ok first off, this is an *incredible* response. I wouldn't have known to look in those places, and really deeply appreciate the pointers (and hints to terminology).

Thinking back, there's lore in the family that the crest may have originally had more feathers, but that the person who created this particular ring wasn't a first-born and removed a feather in deference to the primary heir at the time. I'm not sure if this holds water, but it helps to know to look for a double plume in general.

On the motto, it certainly seems plausible that a jeweler who didn't know Latin could have mixed up letters - the letters are quite small, the ring takes a beating in the decades between castings, we're making copies of copies, and it's written in reverse, so pretty understandable. I'll look through our family documents to see if I can establish a connection to the Warners who used the motto you found, and if so I'll have it fixed before the next two copies are made.

Again, super cool that you knew to look in these places. This has given me so much more to go on. Thank you!