Identify the parts
A flower arrangement can combine a bowl, a support for stems and a separate mount. Ask which elements are included and request photographs of the components apart where they are designed to separate without force. Props used for a photograph should not be mistaken for part of the object offered.
Treat an attribution as a question
The old address mentioned Clichy, a spherical glass body, brass and the 1930s. Those terms describe the old listing topic; they do not provide proof of maker or period. Ask for marks and supporting documentation. When the evidence is incomplete, an accurate description of shape and material is more useful than a confident but unsupported name.
Check the bowl and the planned arrangement
Inspect the rim and the areas hidden by a mount, and ask about cracks, repairs and testing for the intended use. For a dining table, keep the finished flowers low enough for guests to see one another. Test one arrangement before sourcing several related pieces, then retain a reference sheet showing dimensions and the variations you can accept.
For the next part of your selection, read Antique jars and pots: building a collection of forms.