It appears to have been made in 1973, per the date codes on the transistors, and the dated instructions.
The Mark Ten B is a capacitive discharge ignition. What it does is store up electrical energy in a capacitor, then when triggered it sends this energy to the ignition coil. The voltage sent to the coil is higher than 12 volts, so the coil puts out a hotter spark than it would with just ignition points. CDI is not quite the same thing as Multiple Spark Discharge (such as the Autronics MSD box), which sends a few high voltage pulses to the coil with each time the plug is supposed to fire (at low speeds).
This is a used late 1968 Mark Ten. It also came with it's box.
I also have a 1968 Deltakit Mark Ten assembly manual, see the schematic here.