You call 'G-ABCD final.' The FISO says 'G-CD, runway occupied, go around'. You decide you can land safely behind and to the right of the other aircraft, as the Rules of the Air state, so you call 'Negative, contact one on, landing, G-CD' and land
Would it not be more appropriate to make the call:"G-****, Final, visual one ahead, continuing"? This lets them know that you are on final and that you have seen the one on the runway and, for the time being are continuing your approach. You still have the opportunity to go around if necessary or you wish to do so.
Duxford is great! I have to say that I have had nothing but help from everyone there and some of them have very good reason to remember my first solo visit there.

In spite of this I have been made very welcome.