Korg ST-WL Wooden Stand

The stand is very solidly made, with large cast parts joined by heavy metal elements. The solid wooden legs have large threaded screws that screw into the cast base. But somehow the manufacturing (on at least this one in front of me) is such that something is a a little bit off and I need to stick a 1/2cm book under one leg. The legs themselves can be extended to compensate for uneven floors, and have locking discs at the top to make this more secure, but for my particular set, the variation between the legs is enough to means you have to push the leg extension almost to the absolute maximum, at which point it becomes much less stable - which misses the point, of course. I'm using the maximum adjustment just to get it level. It works much better to have the legs screwed in tight and to pad one leg with a slim book underneath.
I tried swapping the legs around to see if there was a different combination that eliminated the problem (two short legs at one end wouldn't be so bad, for example - a slight slope downhill I could live with, if it was solid!) but I couldn't find one. Any which way, I finish up with a rocking back and forth on diagonal corners. At first I assumed the floor wasn't flat, so I tried it on different surfaces, but got the same result.
At some point I might shave a bit off the other legs because otherwise I'm very happy. The legs look great and it *is* very solid. It's just a shame that it's not absolutely level from the factory.