you need 1/16 minimum clutch material on the disc higher than the rivets and referencing the face on both sides, that will get you about 5000 miles before she starts to slip. Should be matte finish with no shiny spots, and no black metal parts. disc should also be reasonably flat say no more than .035 out of flat.
look for black marks on pressure plate either side if you have one. >> dish shaped thing with metal fingers in the center.
flywheel is heavy thing about 30+ lbs with gear teeth on the outside. if it doesn't weigh 30+ lbs then it is an automatic flywheel. no black here either, but can be resurfaced.
note: special bolts on pressure plate to flywheel, flywheel to crankshaft.
Sorry, you didn't indicate you had an engine or your skills level for repairs