Sure, early "series 2" Spider Juniors had the metal Duetto dash, so it is possible. However, I believe the radius along the bottom of the windshield is different, so you'll most likely need to source a dashtop made for one of those Juniors. The rest of the dash could come from any roundtail from '66 to '70. Also, you'll have to decide if you want to use the later speedo & tach, or retrofit the car to use the earlier style cables.
84 Spider Veloce
18 4C Spider