The boards have arrived from JLCPCB and they are gorgeous. They have this matte black soldermask that conceals traces, (not like there is a lot to conceal on the top layer anyways).
Pictured are the Mega Enigma with plugboard and the Nano Enigma Z30, an Arduino Nano to Uno Shield Adapter is included for scale.
Here is a picture of the bottom of the board showing the traces going to the plugboard connector. This matte soldermask looks good, but it is a dirt and grease magnet, let's see how well it cleans after soldering all the components on the board. We will be using solder with water soluble flux