Hi Steve it is indeed a tapered thread my friend...oh joy.
most people take them off and drain the system from the bottom hose...why! because the water taps are prone to leaking and breaking as you have found out. 53K2853 is the replacement plug if you decide to do away with the tap! Good luck getting what's left of the old one out, take your time and go easy.
Oz Cooper
Classic Mini Product Manager UK
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