Reputable Second-Hand Watch Stores that sell Grand Seiko?

I’ll be in Okinawa in a couple weeks, but my schedule won’t allow me enough time to spend enough time to check out Nakano Broadway in Tokyo.

For the watch folks here: do you know of any reputable second-hand / pre-owned watch shops in Okinawa that might deal in Grand Seiko? I’m hunting for a Snowflake Spring Drive (SBGA211), but I’m open to other GS models too.

Naha/Chatan/Ginowan/Urasoe areas are easiest, but I can travel anywhere on the island. Thanks!