Hello Steve, I am only mentioning this for educational purposes, but it is easy to achieve that same symmetry using scotch tape. I was taught by Tim George to engrave the first half of one side or one forth and using bees wax make a pull with scotch tape then tape that down to my plastic clip board, engraving side up, then place a piece of scotch tape over the tape, rub them togther, pull off the top piece of tape and you have an identical reversed pull, carefully place it over the other half of area to be engraved and bang you have a perfectly symmeterical pattern. Engrave the second half of the first side, then repeat the process again to reverse transfer the second half. You proverably knew this already but I thought I would mention it for those who don't.
Steve I will surely post a picture of the knife after completion, and yes the mirror effect was done with the computer in Visio ( I Use Visio a lot ) And ED that sounds like something I will have to try, never done it that way thanks for the tip.
On the one hand, it's more accurate to copy what you actually engraved then to work from a copy of the pattern.
On the other hand, at my current level of competence, it's better for me to work from a clean copy of the pattern in each section then to let my errors accumulate.