OK here are before and after shots of the trailer with RRC alloys and the
Attachment 73407
 
Attachment 73408 D2 alloys.
 
 
The spare winch was a challenge as it is a Toyota ? chain winch with a big spring thingo on the bottom that would in no way go through the wheel hole as it was about 69MM in diameter.
I had a brainstorm and went to the hardware shop and was able to buy a teeny weeny shackle rated at 330KG . I cut the bottom chain link and inserted the shackle with the bolt through the shaft of the spring keeper, so I can undo the shackle if I want to remove the spare,without having to fit the spring and plate through the wheel hole. I will wire up the shackle bolt.
To make doing up the shackle bolt easier I cut a coil from the spring as it only needs to hold 30KG now not 50Kg . I think it is there to keep the assembly tight if the spare loses pressure.
I checked all runouts and the max is 30 thou on one side and maybe 15 thou on the other. Good enough for me.
Regards Philip A