Thank you for your comment and opinions on my rudder linkage set-up, Derek and JimG. !
These arguments are very useful and informative to me just because they are from your precious experience and
knowledge obtained in the past.
I feel generally as follows from my experience about Z bent rod end and rod end retainer as used in the previous image above.
Z bent rod end; ultimately reliable, a bit hard to cut precisely to reqired length with tight 90 degree curve in any diameter
of rod, sometimes apt to be loose in the hole of tiller arm generating a "Play" in the movement.
Rod end retainer; Anxious about loosened hollow screw to retain the rod, easy to set and adjust required length between the tiller arms, actully no play in the tiller arm and whole linkage...
1/2; My old Z bender I bought close to 40 years ago still in service sometimes..
3; Z shaped 1.5mm rod by this Z bender...possibly OK for this dia of rod...a bit hard to set a tiller arm without enlarging
the hole of tiller arm...
A 1.8mm dia rod is terribly hard to get tight curve for me.
4;Linkage in my Lindberg 1/32 PT-109. No problem at all as of today despite of hard sailings on the lake.