It sounds like this is probably a bit heavier than the stuff that I generally listen to. I am glad you were able to find them though. I am sorry that they don't seem to be still together. I have a Tool CD around somewhere, but I can't say as though I have ever really listened to it.
I can't see this being your cup of tea (as we say here) @bozz. There's a little Pink Floyd in some of their other tracks. Which Tool CD do you have?
Lateralis maybe, does that sound right? I think it is a copy someone gave to me.