I also owned a Sapphire in about ‘86 w/ a Souther Linear Tracking Arm. It had excellent resistance to foot falls w/ it’s then unique hanging suspension. The platter was all aluminum. The arm board was just cheap MDF secured / basically dry wall screws & overall quality of construction not great. I sold it for the newest VPI at the time which had noticeably better pace & dynamics.
The Souther Arm was a bear to set up & align; when you changed one parameter, they all changed! It was a good concept & could sound very good. Lou Souther sold the rights to Clearaudio whose linear arm today is based on it.