The item pictured was used up to 1972 models , where you rotate the device to raise or lower the back seat base . During '72 they changed this device for a fixed item which kept the back seat at a preset height.
Hi John. Many thanks for such a comprehensive reply. My previous 96's were owned new in 1970 & 1973 and I had no recollection of this device. My understanding of it was not helped because the one in my project had partly disintegrated. Thanks again to you and Robert for his earlier answer. I am a devotee of the 96 but new to restoration so cannot believe how much help is available via this excellent site. John