The six postcards shown chronologically on this page were sent to attorney Albert Nothomb (see Set: Nothomb) in Liège Belgium between 11/01/1905 and 10/22/1906, a span of about a year, by J.A. Leuenberger. All six cards have a written date on the front in dd/mm yyyy or dd/mm yy format. Ten postcards (not in my collection) sent by Leuenberger to another recipient in early 1906 are shown here.
1905 Crocker-Langley lists "Leuenberger J A Mrs, corsets, 514 Sutter" and "Leuenberger Julius A., waiter, r 514 Sutter." 1907 Crocker-Langley lists only "Leuenberger J A Mrs., corsets, 1716 Van Ness", so possibly Julius A. Leuenberger died not long after sending these cards.
Steve's SF postcard pages: