Doesn't Bowker sell individual ISBNs? Since they are the source, that is the first place I would look.
As for the LC number, I have published a number of books and videos, and have stopped bothering with the LC number. This from a former librarian yet!
I agree with Neil that doing it yourself is a better option. You might also consider selling the ebook on eBay as well.
Rosana, bleary-eyed from relisting all our stuff on eBay after a vacation