Rather than dismantling my bellset 44, I started by looking at diagram
N4308 according to which I wired my bellset 44 (with two "internal" extensions). Unfortunately, I can't see how the wiring you describe relates to this. On what is the wiring you describe based?
Also, I assume you have this wired simply as a stand-alone telephone without any extensions attached, nor for that matter a bell for receipt of incoming ringing.