Found pickled onions without sugar finally. "Three 333 Threes Old Style Pickled Onions"
Ingredients: Australian onions 60%, Water, Malt vinegar, colour 150c, salt, spices, food acid (300), mineral salt. Sugars 4.1g per 100g (must be the onions)

Most of the other pickled onions have around 14g/100g sugar, be careful, make sure you get the Old Style as the other style of Three 333 Threes  has 14g/100g

I purchased these at Woolworths, they are an Australian Company.