1974 Brain Box saves the day.

R is resistor, D is diode band side is direction of flow --->|- C are capacitors , triangle 3 pins are transistors (BCE) you could pop the board out and show us the back side traces and we can come up with a schematic. Once you get the schematic out there, you can overbuild it to your taste, (300V TO-3, Massive isolated heat sink, cooling fan, etc) I know there is a handwritten one out there somewhere. IIRC @KitCarlson made an ignition circuit and there are DIY projects out there. I think the dwell circuit is only thing not a few transistors cant do switching wise. This one has no dwell circuits but look how simple the switching is, 5 components! There are even digital projects out
there. Programmable Digital Ignition

ignition_coil_driver_circuit_diagram_2.jpg