How to 3GS Upgrade FW?

[Rustomrobot]

How would one go about upgrading their 3GS Firmware to 05.13.04 (for unlock using ultrasn0w). Currently I have my blobs backed up
4.0 4.01 4.02 4.1 4.2.1+ 4.3 4.3b2 4.3b3
One fine day I had to do a restore and (stupidly) got bumped to 4.1 w/ firmware 5.14.02.
Fuzzyband says I'm on bootloader 06.04

Am I retard for thinking there is a way to upgrade the f/w to 5.13.03 to unlock ?

Apologies if this is the same question that's been asked 100000000000000 times before.

[HappyTroller]

Theres No unlock possibility (yet) for that baseband. Remember xx.xx.xx is baseband and x.x/x.x.x is firmware. You must upgrade to iPad baseband with redsn0w and you Can unlock. But you May loose your gps and there is No going back

[Rustomrobot]

Ah yes my mistake, about the #'s. I'll just be double fisting my old samsung slider, and 3gs till hopefully there is some sort of break.
Thanks!