Battery over charging and then going flat?

[the evil twin]

Aussie i read summin about an external reg on the left side well but couldnt see it? Pls point this misserable bastard in the right direction.

I'd bet your battery is shagged at the very least.

Beg, borrow, get a battery that is charged up, pop it in and start the engine.
Put a multimeter across the terminals.
If it is under 13 volts then the Alternator is U/S or the sense wire/plug is U/S
If it is high 13 to low 14 then the Alternaotr is OK and your original Battery is shagged