If your bearings show no wear or discoloration then go ahead and reuse them. The important thing is that you get enough grease between the rollers when you repack them. You've got disc brakes on the front so make sure you use the proper type grease. You might want to replace the seal before you put it back together. It's just cheap insurance. Adjust the bearing nut to the right spec after tightening it tight to seat the bearings and back it off. Then re-tighten to the proper spec. The reason your bearings look so good after 80K is because someone has been doing a good service job all along.