Collectors report that the owners of penhome (Simon Gray and Sean Lovell) are regarded as absolutely reliable and do not sell counterfeits; of the Madame Pompadour, no counterfeits are also known. Sticky residues, e.g. label adhesive, can if necessary be removed with cleaning benzine; as a gentler alternative, solvent-based transparent car wax ("paint protection") serves, which simultaneously cares — but not water-based, since this variant is ineffective here. With painted-on gold applications (as on the Pompadour), caution is advised, since solvents can dissolve unsealed lacquers; the same applies to ebonite and celluloid. In case of doubt, the manufacturer or a Montblanc boutique should be consulted for cleaning; for precise application, brushes of size 0 or cotton swabs are suitable.
Related pages on fountainpen.de:
• Patron of Arts Marquise de Pompadour (2001): https://www.fountainpen.de/patron-pompadour-en.htm