X - Non significant
L - 998 engine
2S - 2-door saloon/sedan. (Except 1275GT)
K - I don't know, the document say it should be a 1 for round nose or a 2 for clubman
N - Special Deluxe. Includes the Mini 850 Special Deluxe, the Mini 1000, and the Mini Special 1098cc.
561613 - The sequential build number
A - assembled at Longbridge
It looks to be a special edition mini in the 1974-1980 age range, they were not building coopers at that time however only the 1275gt.Given the vin states a 998 engine I would bet it's a Mini 1000.