The thrust bearing plate on the augers I worked on were a square steel plate with a round collar welded on to receive the bearing. The auger tube had a matching square flange welded on and four bolt holes to secure. With clearance holes it was possible to line up the shaft and centre the bearing plate before mudering up retaining bolts. The only 'close machining' was the bore that took the bearing outer shell, the rest was alignment. Don't know that is much help with that end of things?