Skyway keyed hubs

I have a question. How are the aluminum keyed hubs held in Skyway wheels to drive them? Are they pressed? If so, how much of a size difference is there? Is there a knurl? Are they glued? Is the wheel molded around them? I really need this answer ASAP. The kit wheel looks like it was made to have cheapo flange bearings and then they put a broached hub in instead. I have a wheel just like that for a project I am doing but with no hub and I need to know how to make it have one. Thanks.