BK3A coils, what's equivalent (1976 308 GTB)?

Looking at the BK3A coil (Which isn't manufactured any longer) it doesn't appear particularly special. The circa $1,000 each for them used doesn't justify the 1.6 ohm primary resistance and 72:1 turns ratio unless I'm missing something.

Two questions:

1. If you use a BK2A, which is readily available, of which the electrical specifications are unknown to me, is this a substitute for the BK3A?

2. And what about the ballast resistor from the BK3A, which appears to be also out of production, is an equivalent available?

Thanks for any information.