'Graunchy' noise from front brakes - Advice sought concerning front discs

[mrtask]

Apologies if this sounds like a dim question, but I'm not a mechanic (as obvious from my pevious posts). I've finally got a garage where I can store and work on my two P6s, so expect further stupid questions as I embark on my restoration project!
I changed the winter tyres for summer rubber this afternoon. When the front wheels were off I turned the front discs by hand and they both made a rough graunchy noise. A mechanic mate of mine took a glance, he reckoned it was due to there being a rusty band around the outer edge of the dics where the pads don't touch, but that the discs weren't warped and have lots of life left in them, as do the pads. I noticed the brake pad wear indicator wires were missing.
Is it possible to add wear indicator wires to the existing pads?
How do I remove the rust from the discs?
Might the rough noise actually be the wheel bearings?
How do I ascertain if the bearings are still good?
Any help appreciated, don't hesitate to reply!

 

[The Rovering Member]

Easier & safer to get pads with wear-wires fitted already even if it is possible which I wouldn't have thought it was. I suppose you could drill through then glue wires in but interfering with brake pads probably isn't wise & pads aren't expensive.

Wire wool, wire brush, emery cloth/paper. But if the pads don't touch then it shouldn't be causing a noise.

Bearings could be noisy. (We just replaced both fronts in our V8 as somebody had screwed the hub nuts up tight which wore the bearings out. They should be wound up till they just touch then they're held in place with the split-pin.)

Take the pads out then spin to ascertain if the bearings are noisy though if they are you should hear them as you're driving.