Bicycle Mechanics - Drum Brake for Early 70's Schwinn Twin

I posted this in the Tandem section and was advised I should try it here as well.

My father-in law has decided to restore his Tandem bicycle (Schwinn Twin). The copyright in the owners manual says 1970 so I'm figuring it's an early 70's bike. He called me this evening and asked if I could find any information on the rear drum brake. Apprarently he took it apart this afternoon and cann't remember how it was put together. From reading various threads on here I gather it was made by Atom. I haven't seen the hub so I can't give any particulars. Does anyone know where I can find assembly instructions to reassemble it (preferably with images)? I'm pretty handy when it comes to mechanical stuff and chances are I'll be putting it back together for him. Any help would be greatly appreciated.
Thanks,
Rich

I don't have any written materials but years ago I used to own a bike that had one and I think that i have a pretty good memory about how it works. It's actually a pretty simple design. Exactly what problem is he having with the reassembly?

All he told me is that he couldn't remember how he took it apart.
I'll call him tomorrow and see if I can get more info.
Thanks

I spoke with my father-in-law this afternoon. He said when he took it apart some of the bearings fell out. He thinks he got them all back in but he says he has a space. He's wondering if it's normal to have a space. I asked him to try and take some pictures and send them to me so I can show you where he's at.
Thanks,
Rich

I spoke with my father-in-law this afternoon. He said when he took it apart some of the bearings fell out. He thinks he got them all back in but he says he has a space. He's wondering if it's normal to have a space.

I'm thinking he's OK.

That hub has ordinary cup and cone loose bearings. When you put the right number of bearings into the cup it always looks like there's room for one more. Too many bearings is bad because they rub against one another. Since the touching surfaces are rotating in opposite directions, that creates drag.

Thanks! I'll let him know.

Well my father-in-law says that was what he needed to know. Thank you very much for your help.
Rich