...even acknowledging that the term "in-house movement" has few unarguable examples in the watchmaking world, I would consider the Alpha to be in-house.
Yes, the design and layout of the caliber came from the Peseux 7001 (a very high-quality design, by the way), and indeed in its early days (1990's) Nomos used the Peseux directly in its watches.
But in creating the Alpha, Nomos redesigned the plates and bridges, added perlage and Glahuette striping, blued the screws, countersunk the screwholes, finished the crown and ratchet wheels, added a hacking mechanism, added triovis fine regulation, added the traditional German click and click spring, and adjusted the watch in 4 positions. In addition, by 2006, Nomos was manufacturing 80% of the parts for its movements under its own roof (since increased to 100%, as I mentioned above).
To me, this is analogous in some ways to what Dirk Dornblueth does to the Unitas caliber in his 99.x watches. The difference is that I think Dirk hews to a traditional, handcrafted German watchmaking vision, in which each piece is unique to a degree. I like and respect this tremendously, but I also admire Nomos' vision of marrying traditional and beautiful German watchmaking inspiration with the most modern of precise German manufacturing abilities, at an attractive pricepoint.
-Tom