@Henry Ng Tsz Kiu
Thank you very much for your nice comment! I understand why many parts feel all new from a listener perspective and that is something I have to work on. From my perspective they are not and I can provide a very short analyse.
The introduction motive at bar 1 with the strings is the same that start the first cellos solo which is then reused in the fanfare theme. It is reused in some other places but sometime transformed a little bit. At B you have the main theme that you can hear until the clarinet solo. The idea of the introduction is repeated in the begining of G, which then lead to a longer lyrical section at H, which is reminescent of the first cello solo of the piece, altough pretty different I concede! Then this lead to another fanfare section where the brass reuse the same motive from the initial fanfare and the strings have a mix of this motive and the main theme. This lead to the real return of the main theme at J, which is pretty similar to B. For the rest of the piece you can hear these two motives almost everywhere but again it is not striking I concede.
F section, as well as the bass clarinet solo, are based on the melodic material from the transition b.38-43. (Sorry for this long message I hope you were not too bored by this analyse... 😅)!
Thanks again and have a great day
Jonathan