I tried to be fairly faithful to the original texture, so the skull placement is pretty much the same. I looked at pictures of catacombs like the one you posted, but the original 'skulwal' doesn't really look like that. Not really sure where it's used or what it's supposed to be. The texture I posted was already my second try at it, and I don't have time to start again, so I'll just leave the version I made here. Might make some slight alterations later, though.
In the meantime, I made this:
from this (bafford/btila.pcx):
Not sure about the colors, though.