Pilgrim, your orange Gretsch is on my top 5 list. I love that bass.
Those were originally a 2010 black Friday special at Guitar Center, and that's the only place you can get a new one. A very few have appeared on the used market, but mostly at new retail ($799) or higher. Over the past few months, I and other fans of this model have been watching GC inventories and we've found that as the GC stores sell them, they keep mysteriously getting replacements, one by one. But Gretsch won't tell anyone anything about why the model is available, how many were made, or how long the availability will continue. It's rather mysterious; it's possible they're using the GC special as a test market in order to decide whether to keep producing the 5123.
If that Gretsch gets high enough on your list that you want to find one, check with GC. if they don't have one locally, they may be able to get one from another store. I also know which hard cast fits it - there's a Road Runner case that's very reasonably priced. I think we have one in the local GC and I would be glad to go there and test drive it if needed.