I don't have a manual, but I have owned several Novatron sets, and still own and use one. A couple of warnings:
Make sure to discharge the capacitors before unplugging or plugging in a head. You do that by turning off the power and immediately hitting the test button to activate the flash. Also do this before switching from full to half power.
Some heads will have a half and possibly a quarter power switch on the back of the head (-1 and -2). Never set a single head to anything other than normal (full power). The circuit diverts power through a power resistor to dissipate some energy, and if you try to run too much through them, you can fry it. If you want to run a head at a lower power, you need to make sure to have at least one other head plugged in.
The power pack is designed to balance the power through all of the heads equally, so if you have two heads plugged in at once, each head will receive half the power. In your case, if you have both heads plugged in and the power pack set to half power, each head will get around 60 joules (watt/seconds) of power. If you have one head plugged in at full power, it will receive around 240 joules.
As old as this system is, it's probably a good idea to let it warm up for about 15-30 minutes before using it. Those big, old electrolytic caps like to explode under stress. It's not usually dangerous, as they're contained in a steel box, but they can be very loud when they go. They are replaceable, but not cheap. And if you do one, do them all. Having mismatched caps can be dangerous. And this is probably something you'll want to have a pro do, because those caps can hold around 500 volts a piece! You have to know how to safely discharge them and how to at those voltages, you don't get much room for error.
As for the sync port voltage, assume it's high. Some of the older models ran into the hundreds. Later ones dropped to around forty, and even later ones got into the single digits. It's hard to say what yours is without measuring it, and for that you'd need special equipment. A normal DMM isn't fast enough to read the voltage, since it just hits in an instant, and will report a much lower voltage than actual. If your using a digital camera, or something sensitive to high voltages, use a wireless trigger that's able to handle high voltages. I use a Phottix trigger with mine while using my digital cameras since they can handle up to something like 300 volts.
