Hi Lin
Lucas SA12 Sports Coils have a secondary winding resistance of approx 7.5 Kohms. These were the most common sports coils of the day, maroon-red painted top insulator. They have an approx 3-ohm primary coil.
The earlier HS12 sports coil also seems to be about 6-Kohm to 8-Kohm for secondary winding.
I would say if you are seeing anything from 6-Kohm to 10-Kohm on the secondary then its worth trying out.
Regards