How to UV-unwrap faces correct connected with unwrapped faces?

Hi all,

I hope the title is not too much confusing^^
I’m working on a 3D-Scan model, wich was generated from several photos. There are 2 seperate parts wich need to get connected. Each part got it’s own material and UV-map.
So now I’m trying to connect those two parts where they are intersecting eachother and for this I delete some overlapping faces and fill the holes between the edges of the two parts.

How is it possible to unwrap the new faces that it looks good? So without looking like different textures are used for different faces. This kind of row of faces that I’m modeling between those two intersecting parts is like a scar and I want to hide this scar with the texture from one of those two parts. So this scare just should continou the texture of one part, but in the right proportion. How can I do this? Is there a more simple way to do this, than from hand?
Here is an example of this problem:

And this is how the unwrapped chaos looks like :slight_smile:

I hope it was clear enough and sry for my bad english skills!
Thank you for any help!

what is the model of? might it be a good idea to retopo it? then you could do a much cleaner unwrap, bake the texture and normal of the high poly one to the low poly one, then use clone paint to clean up the bad seam.
(edit) don’t alter the original model, or bother unwrapping it, just start by retopoing it, imo.