A brass-coloured thread that becomes visible when the cap of the Meisterstück Classique 164 ballpoint is unscrewed is nothing out of the ordinary and occurs on originals in the platinum finish as well. The threaded portion belongs to the internal construction and is not given the same surface finish as the fittings visible on the outside. The colour of the thread alone therefore proves neither authenticity nor forgery.
Another frequently cited test is no better: the fact that genuine Montblanc refills fit is no proof of authenticity. Refills too are faked in large numbers, and the makers of fakes naturally stick to the original refill format so that the pens work in everyday use. Conversely, having the refill changed at an authorised dealer at least combines the purchase of a consumable with an expert eye over the pen. For a sound check of authenticity there remains only comparison with a pen known to be genuine, or an appraisal by the manufacturer; individual features never amount to more than an indication.