it looked like a flare end.
i posted the picture via a link but this forum won't let me yet because i don't have enough posts.
okay, posted some fake posts below so i could insert the pic above in my original post.
anyway, i've done at least 2 full turns on that brass nut with the bsin wrench and it still drips. i'm sure i've just about crushed that flare by now.
i guess i'll just have to replace those lines and start again?