The FT-3 had an "on-the-fly" (although it was far from it, pretty jerky movement) adjustment. So it had a base base for mounting the tonearm in and then a secondary locking collar that had the VTA assembly on it. here is a picture:
https://www.hifido.co.jp/sold/12-71621-71059-00.html?LNG=E
Which piece are you missing?
https://www.hifido.co.jp/sold/12-71621-71059-00.html?LNG=E
Which piece are you missing?