Antique ammo question from ocean dive trip

[DeltaM]

35 years or so ago, I use to scuba regularly off the coast of NC.  The ammo in question might be 44-40 though I've never seen one cleaned up or the modern equivalent.  Best I recall, these were off a sidewheel steamer, most likely Civil war vintage.  There were larger rounds, canon, but were encrusted into ammo boxes and other masses and I knew better than to start hammering away on any ammo, no matter how old it was.  I did find some that came loose with some other stuff. 

Looks like the case is brass and the bullets are lead.  There is a bit of a rusty spot where the primer is suppose to be.  I don't know what the primers were made from back then.

Any ideas on what these are?  I usually clean encrusted stuff off with a weak solution of brick (muritic) acid but would like to preserve as much as possible of these rounds.

The modern round is a 9mm with 115gr bullet.

[GASPASSERDELUXE]

If it is from the civil war the one on the left could be a .44 rimfire used in the original "Henry" rifle.

[DeltaM]

If it is from the civil war the one on the left could be a .44 rimfire used in the original "Henry" rifle.

Thanks.  They are both the same or at least came out of the same wad of crustasions.  The rusty looking spot must be contamination from some other ferrous object touching these.  If it is a rimfire, I'll feel better about doing my acid bath thing.