Depends on how "exact" you want to be. I would say you could make a 54.5 work if you are willing to mess around with different stems and/or consider zero set back seat posts. If your attitude is I'll make it fit, then yes I think it will work and it will be comfortable. If your approach is "I want it to be original and won't change anything, you need to ride it before you buy. I subscribe to the former with the result that a wide range of frames work for me, from 51 cm to 58 cm seat tubes. But some of them look a little strange. (Ask Robbie about my 93 Bianchi Campione)