Dear Strapper: I don't think is an arm wand problem ( you can ask about to the Graham people ).
My experiences with Koetsu cartridges is that are not perfect build cartridges. They have small differences between them.
Now, do you have the quality sound reproduction that you know your system can give you?. If not, you can have to check the VTA/SRA/VTF/Overhang of your analog rig and if you have it, then don't worry about.
Regards and enjoy the music.
Raul.