Help pulling sections from Gcode

Ok as seen in the linked post… I made a large booboo. I have the wood fixed (I hope!) and now I need to have that section of the carve redone to get it back correct. I have very little experience messing around with Gcode. This project has been the most i have ever messed with it. All i have done is split roughing and finishing into 2 files…that’s easy…find the tool change and spilt it. And I have found where it does a layer change and split it there. What I’m needing now is a little more involved. I need to take from X760 to the end for each layer change and have it recut that end until I get to 20mm. next should be 24mm and that is where it needs to start everything back normal. I have found where it gets to X760 for each layer but I’m not sure what all i need to make sure it gets from x0y0 to this location and gets to the proper z offset…and does that for each layer going down. I also don’t have my corner to level off of anymore. Digging though i see the top edge is -7.3396mm so is it possible to give the start gcode a different thickness for the touch plate that will make up for that height and keep everything where it should be? Hopefully I’m asking all of this correctly and not just making a mess of it all. Attached is my roughing Gcode.

4 Roughing D-n-J-0361-To My Wife-1.gcode (900.2 KB)

Here’s what I came up with. No clue if I’m right or not. Mostly worried about the transition between layers.

Roughing Fix.gcode (498.8 KB)

I also changed my G92 from Z.5000 to Z7.8396 to make up for the height difference where I have to zero at now.

Edit…setting it to Z-6.8396