Based on your fdisk output, there is only one large disk, which is GPT and has partitions. Your diskutil output is much closer to your GPT output, but the 209.7 MB partition should be EFI not Apple_HFS.
Your Parallels VM may stil work, because it may be using a virtual disk to point to Bootcamp.
The version of Bootcamp assistant is not the same as the Apple drivers you may have installed after you had built your Vista machine originally. Apple will not allow older Windows version on newer Bootcamp to be clean installed, but if you have a BC built originally on an older version of OSX, it should continue to be supported. All Apple hardware may not have corresponding Windows drivers on say BC 3.x, but they would be supported on BC 5.x.
If you are interested in the BC implementation and CSM-BIOS vs EFI vs UEFI discussion, you can find that there are enough references to it in the original thread you have looked at.
You can use the GPT you have, to rebuild the MBR used to boot Vista. In the original thread, there are examples of fdisk -e interactive mode and commands.
If you notice, fdisk entry #2 and GPT #2, the fdisk entry #3 and GPT #3 and fdisk entry #4 and GPT #4 are the same. The '*' indicates that partition 4 is bootable and that is how OSX switches and allows it to be visible as a bootable entry when you press the ALT key. You are missing entries on the fdisk side. Even if you made the entries by hand you may still see a missing operating system error, which is probably recoverable with Windows repair.
I would also suggest downloading GPT fdisk (the tutorial is here http://www.rodsbooks.com/gdisk/walkthrough.html) which helps quite a bit. Disk Utility changes are notorius for stepping on BC installations and corrupting them. Whether DU corrupted your BC instalation, or 10.9.3 did it, may never be known.
On my machine, the output of fdisk and GPT looks as follows. Please make backups of you data before you make any changes.
Disk: /dev/rdisk0 geometry: 121643/255/63 [1954210120 sectors]
Signature: 0xAA55
Starting Ending
#: id cyl hd sec - cyl hd sec [ start - size]
------------------------------------------------------------------------
1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>
2: AF 1023 254 63 - 1023 254 63 [ 409640 - 1452530904] HFS+
3: AB 1023 254 63 - 1023 254 63 [1452940544 - 1269536] Darwin Boot
*4: 07 1023 254 63 - 1023 254 63 [1454211072 - 499998720] HPFS/QNX/AUX
sudo gpt -vv -r show /dev/rdisk0
gpt show: /dev/rdisk0: mediasize=1000555581440; sectorsize=512; blocks=1954210120
gpt show: /dev/rdisk0: Suspicious MBR at sector 0
gpt show: /dev/rdisk0: Pri GPT at sector 1
gpt show: /dev/rdisk0: Sec GPT at sector 1954210119
start size index contents
0 1 MBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
409640 1452530904 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC
1452940544 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
1454210080 992
1454211072 499998720 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
1954209792 295
1954210087 32 Sec GPT table
1954210119 1 Sec GPT header