These boots are from the last HE. The last time I had them repaired they kept their damaged tap- a pair of scuffed and dirty plate boots inlaid with onyx dragons. I also bugged this in game.
I forwarded some info on this BUG report to someone who should be able to help.
Right now, they'll only look pretty again if a shop repairs them. If you repair them yourself, the system isn't looking for that, so it stays scuffy-looking.
I don't have an ETA on a for-sure fix - but someone's looking at it.