I've never seen a black first-generation Raleigh Professional before. I bought one used in about 1972, but mine was white, as with all the ones I've seen over the years. The black Raleigh pro shown in the pictures does appear to have the correct stay arrangement and the fully sloping Cinelli fork crown. (I read somewhere that it was designed by Cino Cinelli for the use of the Raleigh team in the 1964 Tokyo Olympics.) Gorgeous bike.

Editing to add: that bike is an insane value, or would be if we weren't in Bizarro World C&V bike pricing times.