XCV5XX 1929 Romania

The XCV5XX card is from January 3, 1930. Popular Wireless from March 1st, 1930, informs on page 1244 that "XCV5XX is presumably a portable station in Roumania".
On the QSL card he (no name printed, Larcher?) writes "nw QRA: Grenoble (France)" so it seems that he moved back (?) to France that winter.
Also, an X preceeding the callsign sometimes was Maritime Mobile.

SSA QSL Archvies
Courtesy of SM6GSM