That info agrees with the diagrams I've seen Cerberas. The earlier RVC type tacho (used up to 1976) accepts a voltage trigger and connects to the contact breaker side of coil. Addition of electronic ignition to replace contact breakers should make no difference as long as tach trigger remains connected directly to coil CB terminal.
The RVI type uses current to trigger. Typically a couple of white wires on tacho accept feed from ignition switch and onto coil positive. A small shunt connects internally to the wires to sense coil current and so provide trigger. Again addition of electronic ignition should make no difference.
