the P68 has a pretty average trim system. it relies on the tension of the cable around the trim wheel to stop any slipping and has no physical cable lock. therefore if you move the trim to each stop and continue to operate the trim wheel it will misalign the indicator with its actual position.
I have seen pilots hold the trim wheel and operate the electric trim which slides the cable around the trim wheel and misaligns the indicator as well.
I used to check the correct alignment before every flight which takes about 2 mins.
for those that don't know gently trim full nose down, outside align the stab with the neutral rivet, stab trim should be level or slight down.
the fuel system is an even greater marvel of engineering and can cause accidents if not treated correctly.
thankfully been a while since I have had any involvement with the partbanana