If we can believe the OP’s bike is original, the thread over on the C&V board clearly shows a decal on the downtube, stating it is the Olimpiade Record Specialissima.
There is a write up over on Mark Campbell’s Legnano site, showing the differences between The Roma and Gran Premio models. But, that article applies to older models, and not the newer style frames.
https://condorino.com/2018/03/10/rom...nterchangeably.