right I was just throwing ideas, I have never seen it either. my other guess would be the bearing and race may be a part number off from original thus bearing sits deeper and causes your issue.I guess it's possible but I haven't found any references to shims behind the race.
I must admit, in 20 plus yrs or working on rovers and 30 plus in the automotive repair and service field, I have encountered a similar situation.
then again there are not many vehicles where the spindle (aka stubby), is bolted in a similar way as rovers.
another thought. normally rover does not use washers on the spindle bolts or the rotor bolts, if by chance the last person who worked on it, installed washers there then it moved the bolts a tad bit out.
then, the race may have been tweaked to clearance the bolts. now you set the race the proper way and clearance issue arises. from your pictures, I don't see washers on the spindle bolts. check the rotor bolts just in case.