The Zeitwerk servicing is something like 2,500 euros. If you can save much more than that, then it makes sense to go gray.
The only reason to buy from an AD is if you want the more desirable pieces down the road. Regardless of what they tell you, Lange has a list. You're just not on the list, and the Zeitwerk isn't that hot, that's all.
As long as it's not a 45mm+ IWC, it'll be just fine. Those are meant to be wore over cloths, and be as legible as possible. A ladies IWC defeats the point.
What was the WR rating on those watches?
The 1926 Rolex Oyster had 100m WR. Most dress watches of the era didn't use screw down casebacks, though.
Yet today we consider 3ATM to barely be able to survive a splash.
That's just marketing from brands with an interest in selling dive watches
Nobody aligns real screws at any price point. It simply isn't possible to do so and still tension parts correctly.
The $600,000 hand made 1 still doesn't have aligned screw heads, even through each screw is hand made for the watch.
The tubes won't light up until you press a button, so there isn't much to attract attention when you're just wearing it.
In any case, nobody really cares if you don't make a big deal out of it.
This section has a good list of brands. I'm partial to Ressence, although there are many even smaller watchmakers at this price range.