TrueCrypt, What to backup?

I have two data backup drives encrypted with TC.
Both disks are 3TB USB External and has advanced format,which means 4K bytes per sector instead of 512.

Drive #1 has no partition and whole disk is encrypted "\Device\Harddisk3\Partition0".
Drive #2 has two partitions,one is the hidden partition #1 and other the data partiton #2 of size 2.7TB created by me.I was unable to delete the hidden partition #1.I partiotined drive using GPT,so i guess hidden partition #1 has something to do with GPT.so basically i have to mount "\Device\Harddisk4\Partition2".

I want to know what all needs to be backed up so that in the event of a disaster i can get back as much data as possible.

Things i am planning to take backup:
1. Headers.
2. copying 1GB data with Winhex from sector 0 from Drive #1 and #2.so that i can restore this beginning data back in case partition gets deleted or headers corrupted.
3. noting down(or taking screenshot) the partition location in Drive #2 from winhex.so that if my partition gets deleted somehow then i would know where the partition was before and this might help me get my data back.right? and nothing to note in Drive #1?

Anything else i should be backing which can help me in future data disaster?
Anything related to NTFS filesystem which i can take backup of?