[Rick Parker]

At one point a few years ago several folks were having difficulties with the hex wall spliting as the nut were being tightened. I don't recall what was ultimately found to be the cause, but I encourage the use of anti sieze on the threads and tapered surfaces of the nuts and adapter and on the threads and interfering tapers of the wheel and knock off,it will elimate fretting of the like metals.
I had considered making my own nuts from round stock and machining a hex on the end of each one so that a nomal 9/16" socket could be used instead of an internal hex wrench. Just a different way to skin a cat??????????
Or in you case could you make up some "sleeves" that coulds be a press fit on your existing pins? Thereby increasing the OD? I am also unclear if the bolt circle for your wheels is the same as your hubs are currently?