Well the kingpin on the old trucks is supposed to be 10mm so…
I got Trampa 8mm kingpins and trampa 1mm bushings for the inner position between the hanger/truck and then reversed the mbs bushings so it acts as the washer.
you can use the 10mm kingpin but then you have to drill the MBS bushing as those are 8mm ID
Im getting 10mm OD 1mm wall steel tubes to solve the bushing/kingpin issue as then i can just use the mbs bushings in the correct position use the correct 22mm washers and gain a couple millimetre of kingpin thread.
As said its a pain in the arse. but it works and feels better than the plastic top trucks in terms of confidence while riding.