It seems very Ferengi to have a museum gift shop with museum coming soon.
I wonder how binding Freeman's contract with Rom was. Say, in the Disco era… Ferenginar brings Kronos into the Federation. What will unfurl?
You could, of course, argue that Freeman's contract was invalid when Rom called for the original papers… but rule of acquisition 239: "Never be afraid to mislabel a product." would suggest that the validity is a mere minor detail.
In the end a contract is only as valid as the enforcement behind it.
Between two people of the same nation, a court willing to say "Yeah that's valid" and enforce it with the power of the state makes a contract quite powerful.
Between two entities that cannot agree on a means to arbitration, or have that means enforced on them, it's basically only as valuable as their willingness to accept it.
"A contract is a contract is a contract... but only between Ferengi" might seem like a straight up dismissal of another's species rights to be negotiated with, but its also a warning. If the Ferengi authorities don't have the power and will to enforce your contract with a Klingon living in free space, then a contract lacks the enforcement clauses that make it absolute.
So how binding is it? As binding as the parties allow it to be.