G'day folks,
Without seeing the flywheel, I'd pick this as early 1980's, i.e. one of the last few years of full cranks. Could have either points or electronic ignition.
Have to pull the cowling and maybe flywheel off, to see which it is.
The base damage is typical of owners who insist on mowing, without clearing hard objects beforehand.
Alloy bases don't stand up well to high speed impacts.

Agree with you about the carby - there should be an idle adjuster knob there! A bodger has visited his works upon this one...