hfsplus external harddrive has mismatched MBR and GPT

I saw 6 results on SU for the string "gdisk mbr and gpt mismatch" which was less than I thought. https://superuser.com/search?q=gdisk++mbr+and+gpt+mismatch And the two that were close weren't close enough. (Primary GPT is missing, and FileVault volume too and Clonezilla stopped. Can "sgdisk -z /dev/sdx" destroy all the data on sda?)

It seems those cases gdisk did a little more hand-holding than in mine.

I have a external Seagate HD (HFS+) and my Windows 10 won't mount it (MacDrive). From OSX's recovery partition, diskutil and fsck_hfs complain about errors but offer no help, nor are able to fix it. I'm using 10.11 so I think hfsprogs from my Sid is newer (more GPT aware, etc.) probably... From linux, gdisk says;

sudo gdisk /dev/sdc
GPT fdisk (gdisk) version 1.0.4

Partition table scan:
  MBR: hybrid
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with hybrid MBR; using GPT.

Command (? for help): v

Warning! Mismatched GPT and MBR partition! MBR partition 2, of type 0xAF,
has no corresponding GPT partition! You may continue, but this condition
might cause data loss in the future!

Identified 1 problems!

From here, Clonezilla fails at cloning with mismatched GPT and MBR partition, I want to show the protective MBR data (o) and the partition table (p);

Expert command (? for help): o

Disk size is 7814037167 sectors (3.6 TiB)
MBR disk identifier: 0x00000000
MBR partitions:

Number  Boot  Start Sector   End Sector   Status      Code
   1                     1         2047   primary     0xEE
   2                  2048   3519068159   primary     0xAF

Expert command (? for help): p
Disk /dev/sdc: 7814037167 sectors, 3.6 TiB
Model: BUP BK          
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): E780F066-B3FD-4829-8548-AA31DE8F9F80
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 7814037133
Partitions will be aligned on 2048-sector boundaries
Total free space is 3692 sectors (1.8 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048      7814035455   3.6 TiB     AF00  

I did look at, and read, parts of Rod Smith's website, http://www.rodsbooks.com/gdisk/repairing.html.

MBR/GPT mismatches—The MBR and GPT can become mismatched in various ways, such as using a GPT-unaware disk utility on a GPT disk or editing GPT partitions on a hybrid disk. GPT fdisk detects some of these problems when it runs, and gives you the option of how to proceed. Typically, you'll want to use the MBR data or the GPT data, discarding the other type of data. If you need to somehow integrate the two, I recommend you back up the data and write down the start and end points of the relevant partitions so you can re-create them.

From my laymen's eyes, I see that the problem may be what the warning says it is - no matching GPT entry for the first partition of the MBR. I also learned that this 0xEE is designed to protect from non-GPT aware OSs.

Anyway, it looks like a relatively simple task for someone who knows this technology, e.g adding a GPT entry from 1 to 2047. The other thing I notice is that the ends are not the same.

I'm afraid that I need a little guidance before taking the plunge (yes I backed up the data too).

EDIT:

I only use windows 10, OSX 10.11, and various Linux so not sure how it came to be hybridized... I'd be half worth a pure GUID if someone offers a little guidance and positive feedback.