IPhone 4s in recovery mode. Can I restore to 6.1.2?

I have a FU iPhone 4s (Jailbroken, 6.1.2) that mysteriously went into recovery mode while plugged into my MacBook. Is it true that I cannot restore it to 6.1.2? I thought I had valid SHSH blobs (saved from TU) but I get a 1600 error when I try to install a local 6.1.2 IPSW. I have no idea why it would go into recovery mode: no hacked apps, everything on the phone is legit, paid for, and kosher ;-) Are my only solutions to 1) restore to 6.1.3 (no option-restore) and wait for a jailbreakable iOS 7 in the fall or 2) restore it, sell it and try to buy a 4s with 6.1.2 on it so I can jailbreak with evasi0n?