Your opinion on how to tackle this wall fix

Hi, as the subject says, I'm looking for opinions on this upcoming project. The folks have a pretty ugly wall situation leading to the 2nd floor that I'm going to tackle.


None of the 3 sections above are coplanar with another. I'm assuming 1 is old plaster that has bowed and is proud of section 2, which based on the visible screw pocket in the pic below is drywall. Off camera right of section 2 is a doorway so I don't want to mess that section at all, outside of cleaning up the edge I'll join to section 1.





Both top sections are proud of the 3rd below...and that really complicates the matter.



I plan to cut out section 1 as cleanly as I can in regards to the left and top outside profiles, remove and replace with dry wall to remove the visible seam between 1 and 2. If it's lathing like I assume, I'll have to remove that too and then worry about matching the exact thickness of section 2. Hopefully half inch board would be too thin and I could build out from the studs to the correct thickness...but how tough is that going to be?

Then what to do about section 3? Getting that to match seems to me impossible without taking the job to another level, so the best I could come up with was to clean up that edge as much as I can and then route out a relief on a thicker piece of trim and try to hide the difference.

Thoughts? Holes in my plan? In hindsight, my pics could be better, but I hope they get the job done.

Thank you for reading!

 

If I understand correctly all 3 sections stick out at different levels, if so, how much difference between the 3?
If the differences aren't too bad I'd be inclined to remove the base, tape the joints and skim the wall as needed to make it all appear flush.

 

Yes that is what I would do.
Remove the horizontal trim..
Tape , mud and sand the vertical seam.
Reinstall the horizontal trim but move it up a bit to hide the horizontal seam that was not touched.

 

I had considered that, but the bowing at the bottom of section 1 (prob best illustrated in the 2nd pic) has me questioning whether or not I can feather that out.

I guess if it doesn't look good, I can always rip it out as originally planned.

Any recommendations for compound?

Thanks again for the feedback.

 

Regular green lid [all purpose] is the easiest for most to use.

 

The left side of section 2 looks like it might be an unfinished tapered edge. How high from that is section 1? Maybe you can fill that taper, make it flush and tape the joint. I don't have an idea about the bottom.