I bought one of the first run. There was a long thread about them on TB which alerted me to their availability at GC.
The local GC in Fort Collins had sold theirs (in theory, each store only got one in the first issue) but talked them into having one of the Denver stores send theirs up for me. I committed sight unseen, as I love Gretsch instruments and that although orange isn't my favorite color but THAT orange is a lovely color that only Gretsch does well.
Those first issues didn't come with cases, but I found a RoadRunner hard case that fit nicely and shared the part number on the TB thread. I know a lot of people bought them to go with the 5123s. I suspect the case in the photo is one of them.
I really like mine, and it feels good just to hold it and play it. Of course, it received my favorite Labella Deep Talkin' flats immediately. If memory serves, the pickups are ThunderTrons. Also, IIRC I bought a longer than usual strap because the body is a bit deeper front to back than the 335-style hollowbodies, and the bass hung better with a longer strap.
Enjoy!!
BTW - here's the original TB thread:
https://www.talkbass.com/threads/new-gretsch-electromatic-hollowbody-bass.713507/#post10458997And here's one where people were comparing serial numbers. You might figure out the approximate age of the bass by comparing to yours:
https://www.talkbass.com/threads/gretsch-g5123b-serial-numbers.742249/