I'm not really clear about what the differences are between the early Maxi and C.A.R. hubs, and the later Maxi-Car hubs. I do know that the brands were advertised separately until sometime around 1947/48, when ads for Maxi-Car replaced both brands. Maxi hubs have standard cup-and-cone bearings rather than the annualar bearings w/ labyrinth seals that Maxi-Car hubs have.
The hub above is milled from steel - but with holes much earlier than holes were found on alloy-body Maxi-Cars. The familiar dustcaps are also there, but in plain metal. The hub below is a 3-piece alloy Maxi, but is visually identical to a type 1 Maxi-Car, except for the blue dustcaps and the orientation of the pinholes in the dustcaps, which appear to be at the quarter points, rather than the more typical orientation at 2, 4, 8 and 10 o'clock.
