Effective length of Origin Live Encounter

I purchased a very lightly used Encounter MKII a couple years ago and am just now getting around to having it mounted in a new plinth for my Lenco GL75. I'm not sure whether it's a 9" or 9.5" arm so could use some help.

When I measure from the pivot point, the 9.5" measurement comes to the very tip of the headshell. The 9" measurement falls further back, more in the middle of the headshell slots. 

I'm thinking this means it's a 9" arm (Linn geometry) but the builder of my plinth believes it's a 9.5" arm due to overhang. I appreciate help on getting this right so I can give him a definitive answer.

Thanks,