OldEastRR: The adapters didn't stick out of the boxes, one had to look into the boxes to see them. Basically they replaced the bearing brass with an adapter plate and put roller bearings on the axle end. The story I heard was that the lids were removed to remind inspectors not to oil the bearings. The "car toads" would carry an oil can and give journal boxes a squirt, often whether they actually needed it or not, to make sure everything stayed lubed. Roller bearings didn't need it, and excess oil could wash the grease out of the new bearings.
About the only way to model them would be to cut the lid off the journal box, and drill out the center. With needlepoint bearings on our models, that would wreck the trucks. The next best idea would be to file the lid detail off and paint the surface black, to look like an open box. I just ignore them, as the lids are so small most people wouldn't notice if they were there or not, except in close-up photos.
Off topic: We could use some exact-scale wheels for scenic purposes. They wouldn't have to roll, but should have blunt axle ends, plain for the steam and early diesel eras, and with RBs installed for newer wheels. They'd look much better outside shops, in wreck trains, and being shipped than the operating wheels with their needlepoint axles. Since most of these wheels would be rusty from sitting outside, they could be made from almost anything, and wouldn't have to be precision metal wheels.
