I've decided to use the existing ref-by-ajax system for retrieving location information. That means I may be able to remove the abstract stuff from the JSON completely (although it's still there for the moment), making the JSON info very quick to retrieve. I've proposed that we stop diverting users straight to a location page, and stick with popups even when there's no abstract; I've implemented this on dev, because I really need that behaviour for the map. There's now a working rotation function (shift + drag) and I've made the rotation-reset button appear bottom left so it's not obscured by our controls. Coming along nicely.