Gillian,
The Ship Lore Society, 27 Houghton Street, Liverpool, was where my g Aunt received lots of information regarding the Joshua Prowse & Co.(1830s-1850s) shipowners business, but this was in 1939! Also check to see if the Liverpool Nautical Research Society still exists. They provided her with a list of all of the Prowse ships, where built, and when commissioned. Good Luck, Susan