You can also see if there are dandelion leaves from outside (make sure no chemical sprayed areas), or plantain leaves. Those are pretty easy to find and grow anywhere.
I saw a sulcata tortoise devouring a pidgeon on the internet a few weeks ago. I guess they can be opportunistic feeders.
I truly hope mine does not become like that...
I am curious to know about this too, as I have noticed those "transparent" edges on my tortoise as well. So far they don't seem to bother him but I want to know if I need to do something to prevent future scraping.