You might be able to buy a pearl and/or insert from one of the dealers; I'm not sure.
FYI--I've said this in multiple threads, but it doesn't seem to have caught on like it should have: as far as the crystal goes, whether it's mineral glass or synthetic sapphire, the molecular make-up of the crystal has little to do with the distortion you see. All of these crystals, except on the el cheapo 21J versions, are sapphire. Distortion is refraction and refraction is caused by shape, not chemistry.
Yes, the gens have a bit of distortion, but only about 20-30% of what you'll find in the V5 crystal. The reason why the V5s have this distortion is because of the shape of the crystal; from V1-V4 the crystals were flat on the bottom surface and convex (domed) on the top. People complained about the engraved rehaut looking too deep, so instead of manufacturing new cases and recalibrating a slew of machinery to make a shorter rehaut, smaller engraving, and all that goes along with that, they decided by switching to a crystal that was convex on both top & bottom the curvature of the glass gives the appearance that the rehaut is shallower. Of course, one of the side-effects that comes along with this is the distortion. The glass crystals look the same as the sapphire ones do on this model.