Thanks so much for your response here AVB.
Sorry it's taken so long to get back here, I've been a bit sick.
So I pulled the coil off and tested it using my trusty volt meter set to 20k ohms.
With the red probe in the spark plug lead end and the block probe on each side of the coil metal, as well as on the kill plug terminal.
All three locations gave me a reading of 4.75k.
I read online where the readings should be between 2 - 5k ohms and this seemed to be at the top end of those readings.
Is this reading OK or is it too high?