user: Question: Which owner has a description of Mark 1 POS and is dated 1956?
Columns: ['Number & Name', 'Description', 'Livery', 'Owner(s)', 'Date']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['No. 1012', 'Mark 1 RSO', 'N/A.', 'Private Owner.', 1951.0]
SQL:

assistant: SELECT "Owner(s)" FROM "Table" WHERE "Date" = 1956.0 AND "Description" = 'Mark 1 POS';