The thing in Cosford is an wind tunnel model only, I think.
Then, I do strongly believe, these well known pictures showing the F 55 during "pre-flight preparations" show a mock-up only, not the real rocket. It has even no steering surfaces, if you look closely, no inspection hatches, it looks just to neat and to tidy as compared to live German rockets, while silly placed panel lines are visible in some shots.
Only the engine section shot with four 109-553 may show a sub-assembly of an actual F 55 A1.
There were no canards on the built examples. Perhaps the canards would have been placed on a production version.
Yes, there were
probably no canards. But the canards of the 70 cm span were developed indeed, after first test flights and after tests in the AVA Göttingen wind tunnel.
Regards
Grzesio