dude it is so simple its not funny......
its a hollow circle with what ever connection you have on one side and on the other side what ever connection you want. a 1/4" adaptor to a small hollow post and a piece of mirror. as long as you get a stable centroid to your guiding camera the rest is history and trust me i guide on bannanas! So don't listen to anybody that tells you you must guide on a perfectly round star its a load of Cr4p.... My stars tell you the truth. 26kgs of Newtonian mounted on a EQ6pro rated at less.....