(and I think I commented on this years ago in respect to the open barrel of the otherwise non-skeletonised Cal. 71), but my main comment was directed of making use of the arch at 7 o'clock (note: putting a PR hand there would require some kind of mechanical crutches and thus would be no elegant solution (but certainly 'complicated' in terms of parts count;-))).
Keep in mind that my comment was more of an 'inspriation' than any sort of critique. The watch is really well done and lovely executed.
Cheers,
Magnus