Martin -
Thanks for checking, and also for the quick reply. I assume they were in Mexico by 1866 if they were truly musicians in the court of Maximilian. (I know they were there by Jan. 1867 as that is when their daughter (my grandmother) was born in Mexico City, but by then I think Maximilian was on his way out.) If they were court musicians, or at least if Andres was, then I suppose he was not an officer.
Does the "Almanaque" that you mentioned contain only officers' names as well?
Marian