If you grew up in the late 70's or early 80's in Australia, you'll recognise the first part of the title.
My grandmother used to make these occasionally and I used to have Sweet Mustard Pickles in the fridge when I lived in Sydney for sandwiches. Unfortunately, here in the US, there's only two ways to get them. Either buy them from one of the online stores or make your own. I have made it before here and I got the bug to make them again. I actually submitted them to All Recipes and they posted it: http://allrecipes.com/recipe/sweet-mustard-pickles/
Chanin actually put some on a hot dog the other night and said it was great, it tastes like a combination of relish and mustard, so there's another thing you can use them on.
Sweet Mustard Pickles