Hello Mr. Cooper,
surely you're right, but I think that ... yes I am the constructor and the owner of the object, but until it is not paid, even if it is in my house.
I think also that are most important the agreements with who pays rather than advertising.
I also always like to specify that when a model leaves our laboratories is a fully functional, unique, unrepeatable and guaranteed for life.
This does not exclude that someone want to keep it on a shelf.
Luckily we don't need to prove anything to anyone and always thank those who give us trust !
Bye