Residential remodel prescriptive engineering page stamped for an already permitted Murrieta project.

I received a permit for a powder to bath upgrade earlier this year. I did an inside wall inspection on a powder to bath upgrade this summer and found some problems. Upon uncovering these walls and under floor plumbing, I discovered >25% stud and plate cuts on a 6" perimeter shear wall. It appears also the 5' distant opposing 10' long 4" wall was half-ass made into a shear wall (probably to placate the original framing inspector). After I informed Murrieta B&S, they now want an engineer's stamp on a prescriptive repair page added to the existing plans-no more and no less and I have had some trouble finding anyone to help me so I can continue this project. It's a 30 year old tract house. I had to create as-builts myself, because they have all been disposed of, which is typical when municipalities here in SW Riverside county started their incorporation. Riverside County simply disposed of them before the building departments were able to accommodate them. I have attached 1 .pdf with pictures and 1with a plan set as well as 1 .dwg for the A-100 architectural as well as 1 .dwg for the S-100 structural which I had drawn by an engineer who got Covid and died before he completed the stamped page. If you have any questions or need more files-let me know. I will have to revisit the site if you need better pictures.