Gentlemen, I have some bevel setting questions if it's not too much trouble?

I'll start by making sure you have as much info as possible to save the obvious questions;

Razor - Sheffield, 1/2 hollow(ish) approx 1920, carbon steel, straight (ie no smile etc)
Bevel setting stone - Naniwa 1000grit, std not SS or Chosera.
Experience level - informed beginner!
Method - Stone soaked for approx 30mins, wetted in use to keep water on the surface at all times, using circles and x-strokes with light pressure, moving to just enough pressure to keep the edge in contact. One layer electrical tape.

I have now spent a reasonable amount of time attempting to set the bevel on this razor, my first attempt. I have no particular worry about ruining the razor, although I'd obviously prefer not to! I guess I've probably done around 50 circles and 75 x-strokes.

I am getting a bevel, but it's not very even! Both sides are different to each other, but more of concern to me is the 'wavy' bevel along the edge. The bevel is deeper at the heel and toe, but narrower in the middle - on one side possibly not quite there, I'll have to get a microscope to be sure.
Is this a sign of a warped blade? I would have expected the two sides to be opposites if this were the case, that is to say a deep bevel at the middle one side and edges the other.
I am going to lap the stone, as I did kind of make the assumption it would be OK from the factory, but I would have expected the x-strokes to iron out any small defects.

If there are any nice gems of wisdom going then I'm buying today, as I'll be having another go at this tomorrow evening probably.

Thanks in advance
Paddy