There is 2 versions of hollow axle, (not counting 1931 version). One for the ball bearing and one for the timken roller bearing.
The ball bearing version has the inner races threaded and the brake side race is firmly screwed in between the brake anchor plate and a small rim on the hollow shaft that ends the threaded part. The small rim is only at the brake side end, the other end is plain threaded. When the hollow axle is assembled with the race and screwed in the brake plate, strangely enough it does not reach flush with the brake plate outer end, but a fair bit in.
The roller bearing version does not have that rim at the end of the threaded part, it has shallow ledges with grinded surfaces at both ends for the inner races. Both inner races slide on those surfaces and the fitting has to be fitting well, just thumb pressure without slop or bind. If you find play there, it is not uncommon and it should be resolved. The hollow axle is screwed all the way in to the brake anchor plate and ends flush or almost flush with the brake plate outer end.