So, this is a contemporary option but still very much reminiscent of neo-vintage styling. You should look at Nomos. Something like the Tangente, Metro, or even Tetra gives a lot of the same vibes as Orea. They do their own in-house manual wind calibers, which can be seen through optional saffire casebacks.
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Nomos is a good suggestion. Older ones would fit that price band, and, although not regularly fitted with display backs, they're not uncommonly found with them.
To go a very different direction, what about a mid 90s to early 00s Zenith El Primero Prime? This is the cal 420 hand winding version of their 36kvph chronograph, smaller and thinner than most modern chronos, in a 38mm case and 11 mm thick. It's a bit of an oddity to have a movement famous for being among the first automatic chronographs in a manual version, but it makes for a nice view of the movement and a much thinner, dressier watch, if a chronograph can be considered "dressy". Here's a good write up on the model.
Great suggestions, I might have to do that Zenith