I dimly remember something about Owen's Battery - during the capture of the tinclad USS Petrel - having Parrott guns. Am busy now but will attempt to confirm for you ASAP in some of the docs I have, etc.
Mebbe Ed Bearss described it in his Morningside Notes article? I remember reading it somewhere....arrrghghg....
y.v.o.s. and pard,
Ken