Re: A fine piece of German engineering
The Enigma wasn't all that obscure; it was commercially available from the 1920's and its encryption already broken by the Polish Biuro Szyfrów in 1932.
The German Wehrmacht and Kriegsmarine used them, adding further complexity through a plugboard (army) and a fourth rotor (navy) respectively, but its inherent cryptographic weakness was not addressed.
As well as that outpost transmitting the same message day after day, there were the obvious failures like encoding and transmitting the first message of the day with yesterday's setting then re-sending it encoded correctly[0], resending a differently-worded version of a message because of a garbled transmission[1], and certain word patterns that would be present at the start and end of most messages[2].
[0] same length, same sender, different cyphertext. Bletchley Park gleefully rubs their hands.
[1] same sender, usually shorter content length, transmitted shortly after HQ sent a 'please repeat'[3]
[2] 'Heil Schicklgruber' being quite common at the end
[3] A lot of info was gleaned just from traffic monitoring: message size and their frequency, sender location and morse operators. What we'd call metadata now.