But that ship was only ever seen in a 'possible' time line. :p
Yet it's registration (NCC-58925) sets it in the Pre-TNG period. The USS Nobel (NCC-55012) destroyed in the Dominion war, although never seen, is recognised to be an Olympic class starship. (Star Trek Encyclopedia & production staff)
Also, even if the Olympic class didn't exist in canon, why couldn't a ship have similar nacelles? It's not like they're a radical alteration of existing ones. If Baz gave us a registration-range for the prototype then it would be easier to get a nacelle design, but I still think ones similar to the Cheyenne class would fit.