Hey, I love that Skull. You say it was misalighen (I read that after I saw the picture) but I thought WOW That just so cool, love the chaotic outline, though not too sure it needed the rivets.
To be truthful I love all of them. The detail on the gold hanger looks brilliant. I guess you let it etch a bit them painted a stop over it. Looking at the Empire State Building, nice straight lines. Does this technique undercut the area masked out (i.e. are the etched areas straight into the metal or do they spread out as it get's etched more going slightly under the masked area)?
What power source did you use? Car Battery? Could a battery charger / trickle charger work? For some strange reason I have loads of Nokia phone chargers but no Nokia phones, do you think it would work on 3.7 volts so I could at least put these to some use

?