To adjust Cg on my A/C I made the following:
At wing root (fuselage-wing junction) I have made a mark on the fuselage at 90 mm of leading edge.
Then I just put my fingers on the marks I made on both side and that's all ! I had to put a lot of lead with the 55ax, and less with the FS-70...
I fixed the lead as following (picture with 55ax) :