A professional restoration quickly exceeds the value of the 264 (depending on condition between 50 and 150 euros). It is more sensible to acquire on eBay another 264 or a damaged cap top as a parts donor, since this model is regularly offered. In everyday use, attention should be paid to the cork seal: with longer non-use, flush out the ink and fill with water; in operation use water-soluble, royal blue ink as far as possible and rinse at least once a month with lukewarm water, since aggressive inks can damage the fountain pen.