I have also modified XB-XF Falcon caster rods in the past for 510's. They are very large diameter compared to 120Y stuff. The two bolt holes on them don't line up so a black smith use to cut it off and re-shape part of the shaft to suit a shortened application for Datsuns. The besuty of this is that you don't have cut threads - which are a stress raiser point (which you don't get with rolled threads).
I have re-drilled 510 stock strut tops in the past for more camber and caster. IIRC you just spin them 180deg and re-drill them offset a bit.
I have seen some aftermarket and home made strut tops used on Datsuns without a thrust bearing and the statement by Baz at Datsport on their website is correct, they have lots of stiction without a thrust bearing. Not many options here others than spending around $500 on a good setup or making something from scratch. I might see if I can buy some similar to factory thrust bearings and machine something up one day. I have seen a strut tower with a plate welded in that was offset and slotted like a strut top, might be an idea... though not a friendly mod for a car that's to be registered.