Chistopher
malapterurus electricus tonewood instigator
Regarding the function of the vibrola - the nut and saddle slots have to be cut pretty perfectly. Old SGs often had domed thumbwheels so that as you depressed the arm, the bridge itself would rock back and forth, which helped with tuning. Anyway, these are meant more for subtle wobbles, not stuff your Gotoh 510 or Floyd can do.
There's actually nothing wrong with the tuning stability on it. I just don't like the feel of using it, nor the fact that the screw always loosens on the arm in 2 seconds