On the 144 Classique from the 1990s longitudinal lamellae on the feed are correct and no indication of a counterfeit or modification. The removal of nib and feed is not possible without special tools and special materials and should only be carried out by Montblanc itself or an experienced specialist. To clean contaminations from the feed, an ultrasonic bath with simultaneous 'blowing through' is suitable, which also reliably removes smaller solid particles without disassembling the pen. With eBay purchase general caution applies; well-rated suppliers and realistic prices, however, reduce the counterfeit risk; original certificates are no reliable authenticity proof, since they can be enclosed independently of the writing instrument.