After much googling I decided on this recipe from taste.com.au, but I reduced the sugar by 150g or so and it's still plenty sweet enough. This is time consuming but not actually difficult and the end result is AMAZING. Totally, totally, totally worth doing yourself!
So, sorry Maggie. I adore you, love your products and very much enjoy experimenting with your recipes but... I'm never gonna buy your quince paste again.