Would tonearm with same pivot t9 spindl

Be careful, just because a tonearm has the same P2S distance doesn't mean it can use the same mounting hole location.  The pivot on the origin live illustrious mk3c is located in the middle of the arm mounting base which would correspond with the center of the mounting hole, whereas, the Reed's pivot is offset from it's mounting base which depending on the angle of the offset, will result in a different P2S distance.

Dear @radioheadokplayer: The 3P you want has the same P2S distance you are asking for.

Btw, how do you know that the 3P is a true/certainty upgrade over your today tonearm?

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Even if you could find a new tonearm with the same pivot-to-spindle distance, you would also need it to have the same armbase diameter as your old one. It would probably be easier to buy (or make) a new armboard.