A mystery buyer has shelled out more than $56 million to combine two penthouse units at 56 Leonard, Alexico Group’s glass-stacked condominium tower in Tribeca. Together, the full-floor condos on the 53rd and 54th floors measure a whopping 11,892 square feet with multiple terraces and balconies totaling 3,300 square feet. The buyer — identified in property records as South Shore Investments LLC — went into contract on both units in June 2013 and paid a … [more]