Great bike!

First, with the wolf ear head lugs you are looking at 1960 or earlier.
The next question is, is your headbadge 51mm or 56mm? 56mm would but it before 1958.
I'd agree with the above posts that the chrome head tube and fork crown is unusual for a Model B. But I have long learned never to say never with Cinellis.

Here are pictures of my 1958-1960 Cinelli Model B. It is mostly original, but it came with a Huret TDF RD. Hate that thing so I swapped it for the appropriate Canpagnolo RD. I'd also note that my fork crown was more "typical" of the era.

https://www.flickr.com/photos/681231...57627790730860