I'm using adapted top-fill bags in my Hoover Junior, which only takes bottom-fill bags, I took some Electrolux E60 bags (they have a Eureka code, but, I forget what it is!!!), cut off the ends, to make them into open-ended bags, and just stuck them on, and they work so much better than regular paper Hoover bags (C or H1, depending on where you're from!!), cos they have a micro-liner in them, so they don't clog up the moment you turn on the vac...
Changing them isn't fun though, you have to flip the whole vac over to stop any dirt falling out, aswell as keeping the exhaust clear, it's a pain, but that's why Hoover developed the "drain pipe" top-fill setup, which was just as annoying cos it took up 2 thirds of the bag!! My Junior U1104 had one, it was just annoying cos you couldn't fit the bag in properly... :S
Was going to post a picture, but, I can't remember where I put the ones of the U1104 with the filltube shown...