I can add
BL634 Vb CBAF M45 24MU 10-1-42 611S 19-2-42 603S 19-2-42 332S 10-4-42 FACB 28-6-42 ros missing 31-7-42 AST 12-11-42 340S 28-9-43 485S 11-11-43 hit sea damaged airframe aircraft abandoned nr Dunbar East Lothian 21-12-43 FH313.50
Source: Spitfire production list available online
The French units in MTO lost no Spitfire that day (the ones in GB also, but they are covered in the Spitfire production list).
In case you did not check MACR 16170, it did not give any aircraft details, only that 1st Lt Norman E English of 52nd FS hit the sea and crashed, being killed. The USAAF personnel database has no details for his aircraft either (
http://www.usaafdata.com/search).
No SAAF loss for 21 December 1943. 4 Sqn SAAF lost
JG737 on the 20th and 2 Sqn SAAF lost EF611 on the 22nd.