Partition table repair with testdisk and windows recovery

Hi. I recently wanted to update my iMac (High Sierra, late 2012) and this failed. The message: "macOS could not be installed on your computer. A GUID Partition table partitioning scheme is required."

Windows on the bootcamp side failed after a power cut a year ago. I attempted then to repair Windows Boot with various software (including EasyRE), but nothing was resolved.

According to Terminal DiskUtil List dev/disk0 (seems EFI system is missing)

When I ran Testdisk, it indicated that MS Reserved, EasyRE seems to now overlap the EFI System.

I then pressed 'Backup' and the Testdisk interface rearranged the information. The MS Reserved section has disappeared, but, I still note an apparent overlap and duplication, such as MS Data 3x.

Are there logical steps to proceed with the fix, such as checking the sequence of start-end partitions? Testdisk documentation is not sufficiently clear to me. And I find similar discussions are too complex to apply to my situation.

After fixing the MacOS, I would like to see if TestDisk can have a go at the Windows Booting issue too.