62 Valiant 200 / 170 cuin /6 - Odd smell - then dead battery

I have converted ammeter to voltmeter and get 11-12 volts when running
Without the ammeter, you don't really know if the battery is charging or not.
The voltmeter only indicates the voltage where you have connected it.
(if you've simply replaced the ammeter with the voltmeter, that doesn't work as voltmeters are high resistance devices)

Have 12 volts out of the alternator and about 10 from the voltage regulator.
Compare the volts at the alternator output to the volts at the battery positive.
They ought to be the same whether the engine is running or not.
The voltage regulator output voltage will vary. The voltage at the regulator's input should be nearly the same as the voltage at the alternator's output terminal.
You may find the explanation of how the regulator works helpful. Identifying Chrysler Alternators (1960-1976)

You'll have to tell us if the following diagram matches what you found on your car. (I know 1960 is very different.)
The point is to follow the connections from the battery positive terminal to the main splice.
Everything connected to the main splice should be the same voltage.
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When the engine is running, the alternator should be producing power in the range of 14 Volts. Everything connected to the alternator should be close to that voltage.