Example for the Venetian one, you need to gather all the required materials first.
Then you need an R18 shipbuilder that can build parts in the mayor town of a country.
As example, most people never defect so for the Venetian one you need an R18 shipbuilder that has invested money into Venice to make the panel, however that person cannot make a portuguese one if he never defected to portugal (since you need investments in a port to build those panels)
There are players that are '7N SBer' it means they invested in all 7 mayor towns (defected 7 times) so they can make panels of every variety :)
I'm not a florentine expert, but I believe that anyone can make them if they are in 'season'(?) I believe the florentine recipes cycle every day or something.
The HCer is the main skill, therefore has to be the one invested/making the panel. SB is the secondary skill that can be leeched, so doesn't need to be invested.
Comments
3 original ship permits
2 special ship paints
1 iron plated panel
As stated above you need investments in the port as well as r18 shipbuilding and r18 handicrafts if I remember correctly.
Someone with casting would need to be invested for the metal.
mankind never learns...