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,
smccull
millercarbon,

Thanks so much for the link. There is also this link, which is where my confusion is coming from...

https://www.originlive.com/hi-fi/tonearm/dual-pivot-tonearm-encounter/#tonearm-specifications

I am trying to figure out if mine is "standard length" or not. Thanks.
Measure the tonearm's effective length by drawing a straight line from the arm's pivot to the center of the headshell slots.  Please see the attached diagram.  https://www.analogplanet.com/content/tone-arm-geometry-101
The 9 inch will have an effective length of 229mm and the 9.5 inch will have an effective length of 239mm