Are the hubs and axles from early steamers with 90 degree quartering different from those of latter production steamers set at 87 degrees? Or is the hub simply rotated on the axle to the lesser degree point?
If the hub and axle serrations are not the same from one production time frame to other then I guess it's possible to end up with a mix and mismatch of parts on an engine put together from a parts bin. This could make itself perhaps most evident on a 4-8-4 with nearly impossible to achieve correct quartering.
