For the 138's bigger L184 (10x10) sibling that I have, all five condensers have the label reading correctly with the convex side up and flat side down, an they do not look to be changed from the factory configuration, unlike Mike's situation.
So yes, when combining condensers the upper one has the label upside down as you indicated.
If you have difficulty reading it upside down, just pull it out to read it...
Mine has a head that points at the ceiling but when I'm lazy I take an iPhone picture and then rotate it an app.
Everytime I find a film or paper that I like, they discontinue it. - Paul Strand - Aperture monograph on Strand