Metal skinned elevators were introduced on the Spitfire production lines, as Spitfire Mod. No 1388 and Seafire Mod No 357, starting in June 1944: initially, fabric covered elevators were converted to metal skinning: this was covered by drawing No. 35120 SHT 3. (Note: The added green boxes to the left highlight the various changes made and when; the purple box shows how the original fabric lacing holes were filled with flush rivets; the red and orange boxes are self-explanatory.)
In October 1944, drawing No 35120, SHT 6 was issued for the definitive, metal skinned elevators: Spitfire Mod No. 1388; Seafire Mod No 751
Thus, any Spitfire & Seafire built after June 1944 was more than likely to have been fitted with metal covered elevators.