Hi mate - a couple of thoughts:

1) It could be the heat shield. I t has have a gutter/channel in it (the heat shield is folded to produce a lip/gutter/channel to allow water to run off) - mine had rusted to bggery and were also bent and touching the discs. Try pushing them back with a screw driver poked through the wheel spokes. I cut the channel off of mine as it was full of crp and rocks and rust (it's about 3-5 mm - so still functions as a brake heat shield....).

2) Could be a wheel bearing - have your brakes gone spongey? If a wheel bearing goes really bad then it will take two pumps of the pedal to go hard - first one squares the wheel in the bearing - second one does the braking... but they'd be pretty far gone for that to happen (had it in a track car a few years ago).

I'd try pushing back the heat shield first as it pss easy to do, quick and free...