Here's another option to the keeping the originals in place as long as possible :
Cut a couple sections of an old bicycle inner tube to desired length . Just slip them over the OEM dust shields . You'll likely have to stretch them to get them over the shields . Trim excess . Done .
And , usually , the 'fix' even looks decent . ;)
I've used the same 'method' to extend the work life of handlebar grips that have cracked from sun rot , with excellent results . :D (edited)