Looks like future razor blades to me. Don't know that I would want to be the first to hit an LP tank with a torch but....
just filler up with water and you should be ok. that's the way a lot of people cut 55 gal. drums. fill up completely with water, then get the torch out.
If you look just above the 05 it looks as if someone has already cut out a piece of the skin. I would assume it would be ok to cut up. Just my opinion, for what it's worth.
My guess is the scrapline, too. Like Alaska said, it appears that a few pieces pieces have been cut out already. If not, that's one eeeevil tagger.
