In the 1963 Legnano catalog there are 3 tiers of road bikes, top to bottom models - Olimpiade, Gran Premio and Mezza Corsa.
The Olimpiade has forged dropouts and would have a Campagnolo crank. The Mezza Corsa had no chrome. So yours looks like a Gran Premio. Interesting that Randy's has forged dropouts.
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The one I'm working on has chrome stays (and fork), serial (FM6883) is not very far from the op's, same dropouts, and there is no way it is a GP or Olympiade as it weighs just under 7 lbs for the frame and fork.
All the pics of GPs on the condorino site look to have forged dropouts.