If you want scale drawings, Arthur Bentley is working towards a full set on all Spitfire Marks, but I’ve no idea how far he’s got. Model Aeronautical Press (MAP) did a set, under reference no. 3006, and their drawings are still available (under the same catalogue numbers) from My Hobby Store.
Without looking at it, it’s difficult to be certain, but file AIR 10/3490, in the National Archives, is listed as “Schedule of spare parts 1st. edition” on the 21 & 22, with AIR 10/4892 and AIR 10/4899 shown as addendums (addenda?)