According to info Q posted previously, here are the options for signing a FISA warrant (see pic):
Director of the FBI: James Comey
Deputy Director of the FBI: Andrew McCabe
Attorney General: Loretta Lynch
Deputy Attorney General: Sally Yates
Assistant Attorney General for National Security: John P. Carlin
Statement is from here:
https://intelligence.house.gov/uploadedfiles/fisa_title_i_summary.pdf
(Sorry in prev post, clipboardimage was error)
So my guess the redacted signatures are likely Lynch and Carlin since neither of them is on your list as having signed something.
And I can't help but wonder if one of the redacted signatures isn't Hussein himself…that'd be fun.