Nice you found the ring, maybe next time your necklace could be tried as a pendulum. I say this because, several years ago, I was trying to help a girl on the Internet find a lost money wallet. She was just so sure it had been stolen. No photo of the place she lived, so had to depend on mental dowsing. After checking everywhere found nothing, then she took off the necklace and tried seeing if it could work like a pendulum. Nothing happened at first. Then after moving a couple times, stepping to turn a little...the necklace started swinging. She found the ring, that time it was were already had been checked. Also I was right that time about the location.
Anyway, I kept having a strong feeling your ring was still there, thought it my be in some kind of corner table with drawers or a corner stand with things, containers on it.. Glad you found it!