+1 to Randy and Grand...my Merckx is Reynolds 753...which is among the lightest lugged tubesets made (maybe the lightest?). It was ridden professionally in the Tour de France. Current weight is 23.5 pounds and I doubt it was much under 20 when it was raced. People seriously exagerate vintage bike weights.
My Merlin butted ti with 9sp Dura Ace isn't much under 20 lbs. I think I last weighed it at 18.9. Granted tubulars would shave it further.