The condenser was added to reduce the RFI in radio equipped vehicles. You can keep it on or remove it, doesn't matter as far as chargeing goes.

re. determineing what voltage the gen is.

Secure the gen in a vice. Ground the F (field) terminal.
Hookup your VOM with the negative lead on the grounded F term and the positive lead on the A (armature) term.
If you spin the pulley by hand you should see 1 to 2 volts. This will tell you that it can produce a voltage.

Take an impact wrench or drill or anything that can turn the gen rapidly, using a socket on the pulley nut spin the gen over as fast as the tool will spin it.
If the gen is producing voltage it will "resist" the power tools spinning motion and try to slow it down. This is good as it won't allow you to over spin it and it also indicates that your spinning it in the right direction.

Check the voltage while it's spinning. The gen will output approx double the desired regulated voltage, i.e. a 6v gen will make between 12 - 14 volts, a 12v gen will make between 24 - 28 volts.
14 volts or less = 6v, 24 and above = 12v.
Good luck
Dave