Hello "strangers"...
I think what was implied above is that horizontally, an increase in pressure on the thrust surfaces further increases any inaccuracy and/or wear. (increased axle wear? Tip wear, where it spins on jewels?)
I pretty sure people 100 years ago would have kept it horizontally under their hat if it improved the accuracy. A good pocket watch was a big deal back then.
I once read on a watch site, the vertical display hangers, were not just for display. I cant refer to exactly which site, total reasoning. or the accuracy of the statement, but it seemed logical enough to me to help me decide to keep mine on display -vs- in my dresser drawer.
Proper care will be needed to keep it running "forever", just like that engine.
Who knows, in a hundred years or so, a new caretaker may tell stories about the early caregivers runs....all while using your watch to time those very same runs.
Hey, ask the jeweler about storage (and relay the answer back to us.. please) If its repeated info..oh well, repeating info, often helps in retaining it to memory.
Also, ask about getting your name engraved too. Then, in your will, give it to the train! You just might become a famous portion of that trains history that way 
( IMO, it sure would beat 15 minutes of fame today 
).
No photo? 
