Good to have those cuttings. CARMELO was previously reported as launched 13 Apr 1876.
MARNA: at that time Lloyds Register recorded 'date of build' as launch, and newspapers reported launches. She was launched 15 Dec 1879 so by Austin & Hunter, but registered 2 Feb 1880, near enough a completion date, so by S P Austin & Son. My convention is that the 'builder' is the company that completed the ship, not the one that launched it.
My understanding is that hulls were built at the west end of the yard, with ship repair at the east end.