Exactly bumpy scales and a bit raised middle is pretty sure normal but I have big waves on top of that. I'll call today and see if I can go next Sat. Thanks for your help!I checked mine and although the scales are slightly bumpy and there is a slightly raised bit in the middle which I think is the spine? The stingray part is fairly taught against the bag and doesn't have any movement that could cause waves.
Did you pop back to the boutique? If there is a problem I'm sure they can exchange it.
For what it's worth stingray is the most amazing and hardwearing leather. After over 18 months of pretty heavy use including days at a time rubbing against jeans, zips etc the exterior of my bag still looks brand new. So definitely worth investing in!