It is absolutely worth cleaning up and restoring.

IIRC Graftec never sold complete bikes, only the frameset. So you don't need to worry too much about finding all of the 'correct' original parts. Pretty much any late '70s components would be good.

The Graftec lugs were stainless steel so galvanic corrosion isn't an issue like it would be with some of the aluminum lugged carbon frames. The only problematic spot I remember is at the top of the seat stays where they connect to the seat lug. There's a narrow section there where they can break.