For some time, I have believed that all genuine black Constellation dials came with gold lettering, however, thanks to Per Baun Christensen, a Danish collector of Constellations, I have had cause to change my mind.
The dial featured in this post belonging to Per is a genuine dial and this can be determined quite easily by examining the script and other features on the dial. The close-up of the Constellation script shows authentic serif font that matches perfectly with factory specifications. Complimented with rhodium skeleton hands and double baguette faceted quarter-hour markers in rhodium, the dial has aged evenly. The case, movement, crown, dial and hands are all to factory specifications.
Gold lettering is clearly more common in black dialled Constellations than white lettering, because it appears that more black dial Constellations were produced with gold hands and markers. The standard appears to be that black dials with rhodium plated hands and applied hour markers have white lettering and those with gold hands and markers have gold lettering.
The example shown here is in stark contrast to most black dials with white script seen today. Refinished examples vary in quality and accuracy, with most being detectable at a simple glance.
So, thankyou Per Baun Christensen for helping us add to the knowledge of black Constellation dials!