I'm positive it's negative

the fun and international posts I have had about the question of polarity
I have been considering changing my radio to something with FM and a CD or cassette player

Thanks has to go to everyone who gave advice.
It’s a negative earth, I have just checked, however the person who restored it before I got it has used an earth strap as I would expect for the negative to the bulk head and another negative connector to go to the coil, must have been what they had left in their box of bits!