If you have original drum brakes on the front of your mini with twin leading shoes (2 cylinders per drum) this is the kit of 4 tension springs you should change. Originally a double spring type they are now single spring coil per item but more efficient.
The small conical spring holding shoe to the backplate is
27H3753.
For pre 1964 cars with a single cylinder per brake drum use
17H8092 springs or
GBK1834