I’m not sure epoxy driver centers would be a good idea. pressing the driver tires on would likely distort them, plus they won’t conduct electricity. There is quite a bit of info on scratchbuilding drivers out of brass here… http://groups.yahoo.com/group/brasslocobuilders/ There is a current discussion going on now on the subject, plus a search will bring up a buch of older threads.
I think you need to join in order to view the list, but it’s well worth it.
Several years back there was an article in Mainline Modeler magazine on scratch building a locomotive, including the drivers. The wheels were cast epoxy with machined tires.
Recently on the brassbuilder’s group, there has been a long discussion on machining drivers, so I 2nd the recommendation to join it.