I'm no expert but I've gathered up a few of these in recent years, so I'll take a few guesses...
Nice stamps by the way. The three CSA #11's certainly look good and should be easy to verify, just be sure they are intaglio (engraved) stamps - the ink will appear raised in oblique light. When the printing is weak like the one in the middle, it's typical of a Keatinge & Ball printing, inferior to the Archer & Daly examples, especially confirmed when the cross hatching behind the portrait becomes a solid mass.
The U.S.P.O. Despatch (probably #LO3?) should also be engraved.
The 5c CSA looks sharp enough to be a London print and the pale greenish blue color supports that conclusion too, so CSA #6.
Regarding the gash above the "N" on CSA #11's, in theory they should all look alike. But I suppose that there must've been some bits of detail remaining on the master hub so that if it was transferred deeply enough, a little bit more detail still showed despite the damage. It's a nice little identification aid when looking at rough online images.