Vintage Ivory USA Wine Cask Wall Art *SECRET SAFE*

I'm not 100% sure what this is exactly, I displayed it with my collection of pottery wall pockets. I have seen similar things in Italy for dispensing wine. It says USA on the back and it's also numbered but the glaze is so thick over it, that it's hard to make out, it looks like #340. If you happen to know what this is, I would appreciate any input you may have. I personally stashed jewelry in the back, it has a very large pocket and worked great for that. it has either a hairline crack or it's a crazing line, I can't tell for sure (pictured). It's 9 1/2 inches long and 6 1/2 inches wide at it's widest spot and it's approx. 4 inches deep. It's in very good condition and worked well as a hiding place!In any case it must be a bit rare, because I havecollected old pottery for many years and have never seen one like this.