1998 Ford F-150 clutch pressure plate found black fibers?

I took my 5 speed transmission out of a 1998 F150. Then looked at the pressure plate, and there were black fibers hanging off of it, I've gotten quite a bit out by now. I'd say about a golf ball size worth. Was wearing gloves because I know it's harmful to your body, that is, if it's the clutch dust. First off, are these fibers from the clutch? Second, Could the slave cylinder leaking(without boot) make my clutch wear faster? Haven't taken the clutch off yet, but these fibers seem to be tell-tale sign to replace the clutch and slave cylinder.

Common sign of the friction disk being worn out, the fibers being part of the friction disk construction, Trick to doing any of this vintage of Ford truck clutch assemblies is do it all, don't cut any corners to try and save a buck, as it will come back to bite you in the @$$ later, send the flywheel out to be surfaced at a machine shop, buy a complete clutch kit, meaning friction disk, pressure plate and throw out slave cylinder assembly, Trying to be cheap will cost you twice as much in the long run, and this also means the cheapest kit you can find at Vatozone, go to a real auto parts store or use OEM Ford parts