Can you help to identify these frames, bikes or parts?

Been asked to look at this for a friend, but all they don't know a lot about it. They were told it was an AMP3 bike - but having contacted Amp Research, they say it's not one of theirs.

Any ideas would be gratefully received...

And the rest was Shimano XTR.

Cheers,

Simon

interesting bike. it's titanium unless the photos are deceiving. Steel would have some rust somewhere and i can't see a spot of it. FYI, but those are interesting parts. that fork is a classic. i'm sure it rides like shit now, but it's a classic.

nice frame. nice welds.