I cant say for other countries Stein but in the 1850-60's in the UK, all ships had to be registered with the government (Board of Trade), this was done by the port region and information was collated by the Harbour Master and documented and archived with the board of trade, the information made up a somewhat haphazard national registry of ships - by way of a huge paper database of ships, type of ship and sailing rigs they used, cargo carried, and most importantly for the purpose of sale - the Master & Owners names & location.
I am happy to share a few examples of ships registration documents and crew agreement from one of my ancestors during this period if that would help?
Please PM me with your email address and I will send the details.
Ships for sale in the UK normally appeared in local port newspapers and in local nautical publications such as Turnbulls/Christies annual Shipping registers, or similar Lloyds publications.
I think you can see some annual Turnbulls registers online,
heres a link to the 1856 one.