Awesome.. good thinking with the practice block. When I saw that piston I though it was yours for a sec! 
Looks good but not sure how it's supposed to be as I've never done it but looks like other pics i've seen... How much was the honer and how long did it take you to do one bore?
That piston is from my block

number 4 is pretty much the same but has caused no damage.
The honing tool was £25 from machine mart which is fine for a few blocks, any more and you want snap-on or somthing of a similair quality (according to a mechanic I spoke to today). The quality of the stones varies too, the ones I am using are a medium grade and medium quality. As for time per bore it depends on how much of a tolerance you have, I was on this for perhaps a 1 min which has taken off the glaze but I have not managed to create the 45deg cross hatch, prehaps a little closer to 20deg. If you watch a video of them doing this on a Motocross engine it will be in and out for 20 seconds if that so not quite sure whats best?