Just realized I posted this summary in the wrong thread, so here it is in the correct thread.
I got three different pairs of bearings from Jeff Kane, two were just sleeves, one longer than the other, third was a flanged bearing which was a total bust! As others were telling me, there's simply no room for a flanged bearing on this engine. But at a buck a piece, I just wanted to see for myself - it could be done, but you better have some serious machine shop skills!
I used the short ones, only slightly longer than the thickness of the brush plate - drilled 0.006" under the armature diameter, cleaned up the hole, wiped a bit of Gorilla 5 min epoxy on the inner rim of the hole and pressed in the sleeve. Looks so good you would think Lionel did it!! With the short sleeve, I found alignment was touchy - when I first assembled and screwed things down, the armature was binding. So I while the glue was still setting up, I loosened things the screws, pulled the brush plate up away from the side plate but still sitting on the shaft, and eyeballed the brush plate. It was pretty easy to see which way things needed to be tweaked. I didn't try the longer ones but will on the next install - their advantage would be easier to do a final positioning in the armature hole to get perfect alignment.
So the sleeve bushing worked great, the nylon thrust collar worked great but required careful encapsulation by the epoxy, and the flanged bearing just wouldn't fit.
A Lesson Learned: these old brush plates were assembled by sticking a solder terminal under the brush holder and installing both into the brush plate, then applying a four pronged crimp to the opposite side. While this probably made a nice tight fit at the factory, over the years the solder lug becomes loose - loose enough to cause intermittent operation of the motor in my case. Recrimping is next to impossible because of the delicate nature of the brush plate, and how close the brush holders are to the edge of the plate. Yep, broke one trying it with hand tools. Donor was in a box and it's solder lugs were tight, so the day was saved. I think with the proper crimping tool in my press, this would have been easy - not sure what that tool would be, but it is very similar to the way Lionel installed the flanged axle bearings in 600 series diesel side frames.
Thanks to all for the good ideas and recommendations! Fun stuff, these trains 
