Special instructions: From the answer to each across clue one letter must be omitted wherever it occurs (often more than once) before entry in the diagram. To the answer to each down clue one letter must be added, at any point but not unchecked, before entry in the diagram. Definitions in both across and down clues refer to untreated answers; cryptic indications refer in both to the answers as they appear in the diagram. Numbers in brackets show the length of untreated answers, both across and down.
19a Sir twice errs with cups - we stick rigidly to holy writ (12) I have ?C??????S?
5d Mates were with'orse coming in second (7) I have ?A?K????
Grateful for any help