difference between axles

[dwcsr]

The bearing numbers you listed are for Ball type bearings, 2 cups and a cone. The differences in the spindles is that from 41-52 is they changed from huck brakes to Bendix and the upper hole was drilled to 1/2" in 52. 47 to 55 1st axles are different than 55 2nd to 59 in that they stopped using bolt on spindle stops and the spring pads were drilled parallel and not on a angle like the 47-55 1st. If your changing the hub to disc then you need to go with the bearings in the kit.

These are the Roller type bearing numbers for the stock hubs
909052R Set inner - MBS (Japan) 1946-59
ID 1.2815 OD 2.963 Set Width 1.145

909001R Set outer - MBS (Japan) 1953-59
ID 0.750 OD 2.08 Set Width 0.708

6064 Seal inner - National