Does anyone here have a link for iPhone 2,1 (3GS) SHSH Blobs for iOS 3.1.3? And before you say that SHSH blobs are unique to a device and a downgrade won't be successful, there is actually a way of downgrading your iDevice *tethered* with someone else's SHSH blobs via iFaith with your iPhone 3GS/4 or iPod touch 4th generation, according to The iPhone Wiki.
https://www.theiphonewiki.com/wiki/Tethered_Downgrade
(Reference in '3 Method')
https://www.theiphonewiki.com/wiki/Tethered_Downgrade
(Reference in '3 Method')