Hi DaveW,
" Instead of cable ties I used a screwdriver, just in case the rebound spring slipped"
You can bolt the kingpin and the lug plate with the Nylstop at bottom end and use a screwdriver at the top of the kingpin. It seems more secure. I did it by this way.
Worn stainless kingpin with Devol bushes after 50 000km. Replaced by chromed kingping and bronze bushes.