Originally Posted by dddd

As a The Dura owner, this thread got my interest, and what an interesting bike!
All of the paint and lining with color accents, along with the silver-painted "socks", is just like on mine.
Coincidentally, today I sold a Motobecane Mixte with just that kind of toptube/mid-stay arrangement!
When I found my The Dura 11 years ago, there seemed to be zero information on the marque at that time, but now more is known (thanks for that).

Your crankset and bb will do fine with periodic oil-can lubrication, perhaps every year or two depending on usage.
Do make sure that the cotters are well-seated, alternating hammer blows to the heads of the cotters with some torque on the nuts until the nuts stop wanting to turn.

The Allvit derailer would normally sit at more like a 5-o-clock angle, might just need to be twisted forward after it got left pointing to 7-o-clock after a wheel change(?).
A rearward disposition as shown would only be needed for use with a larger 32t freewheel.