I often mix 40 mil of oil into a 1 litre former metho bottle for easier top up. My two stroke oil bottle has a precision chamber with a scale you squeeze the oil into through a built in tube.
That 200 mil bottle idea is a good one, as long as you use 25:1 equipment.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!