The piece I had was in binary form - first half in G minor, second in G major. There were a few accidentals as well, and some of the fingerings needed weren't always the most obvious fingerings for a given note (long Bb, anyone?). It was also titled "gavotte", probably to wrong-foot those clarinettists who aren't familiar with Baroque dances.
The approach I took was to buy some of the study books from the Grade VI syllabus (Dip QS is, allegedly, a Grade VI standard piece). I don't know what the sax equivalent is, Scaramouche, but I found the second of the Chris Allen Progressive Studies books to be very useful - about the required standard of difficulty, and (with the benefit of hindsight), not dissimilar in musical style as well. I think the syllabus blurb is something along the lines of "pieces are especially written for the exam, but may be in a pastiche style", which I interpreted as "likely to be modern".
The other advice is don't panic! Five minutes is enough time to play through the piece a couple of times and to focus in on some of the more difficult bars.
Oh, and don't be self-conscious about making lots of noise during the run-through. Although you'll still be in the same room as the examiners (which I found a very

experience), they really aren't interested in what you do during your preparation time, and are likely to use the five minutes to read your programme notes before your
interrogation cross-examination viva.