F*ck me you lot are making this complicated.
Take the whole hub assembly from a 280mm equipped 4X100 car and bolt it up.
Should be fine with OEM 15" rims.
Won't need any grinding or cutting back with a lathe.
Cars you should be looking for in the scrappers are TDI SEATs, Passat3s and other bigger VAG group stuff which is still running 4X100.
This kit just bolts up, no titting about making it fit.
You will need the 22mm master cylinder to keep the pedal travel right, if you're coming from 239mm set up.