i have bent the clasp downwards on a "manhattan socket7/370 cooler" and managed to fit it on socket 4. it even fits on socket 7 just fine after the bending. i'm not sure if there's any long term issues with using this on socket 4 due to possibly too high mounting pressure, but it seemed fine for quick testing.
a word of caution though, on the batman's revenge board there is a tiny smd capacitor right under one of the plastic tabs which can break off very easily while mounting/unmounting the cooler. it happened to me and i was able to solder it back on, but it was very annoying due to the position.
i also have some other "bent wire" style socket 5/7 cooler like in Horun's post, but was not able to make it fit on socket4.