I made these to level up leathercraft, and since they sell for ~500 each in Jeuno (or NPC for 608 with high fame), but cost 2k to make, I tried to desynth them.
NQ is a cotton thread, which sells for 12k/stack, never got an HQ though, lvl 35 leathercraft
Edit: I managed to get an HQ at lvl36 leathercraft, which resulted in a Wolf Hide
I also got 0.1 and 0.2 skill ups while desynthing some at lvl 37 leathercraft, so the cap is at least 38
Edit to the edit: got skill ups at lvl 38 also, and a few HQs that resulted in cotton threads.
So: Lightning Crystal + Wolf Gorget NQ = Cotton Thread HQ1 = Cotton Thread HQ2 = Wolf Hide
the DEF on minor items like these are not worth looking at. If you are really interested in DEF being a tank you should look for VIT instead. The exception is a NIN blink tank who should be looking for EVASION. This gorget gives neither which doesn't make it worth the gil to get. If you're a PLD or WAR go for the Medival Collar at lvl 35, sam def and VIT+2. Not sure what a NIN should be going for - ask one of them.