An exellent find, Mr Crighton! And, your 1891 discovery is actually a DoubleWhackTM, since Liebhaber is only found in that one family in that census, and of course Barm is unique, too.
As if such excitement isn't enough for a Wednesday, Daniel Liebhaber, Barm's son, is listed as "Principal of the Berlin School of Language" - which one would assume to be a pretty unique occupation as there's only ever one principal for these kind of places. But of course, without an occupation index for 1891 we'll never truly know - sad that we have to live with such perpetual uncertainty.
cheers
Paul