Hi - I will re-measure, but I get slightly different numbers.
Fronts to Mains 606m
C of G 65 mm forward of main wheel axle
Wt to be added 706 mm forward of main wheels (this is front side of forward bulkhead as I will need to add about 400 gm).
Not sure if the differences might be due to different squat angles of wheels, or differences in levelling tolerances?
I think that this thread will be a great help to those of us using the Xicoy cg system - thanks for starting it.