Ouch.
I don't know how helpful I'm going to be.
This is going to be a difficult and somewhat risky repair, no matter how you slice it.
I'll try to give you some "good enough", "this might work" ideas.
FIRST:
Here's my short list of things to beware of, and then some suggestions to try to fix this.
As I understand it, you have "run out" BOTH WAYS? The edge of the driver wobbles in and out as it rotates because the driver is not pressed perpendicularly onto the axle, AND the driver rolls kind of like it's an egg shape because the axle is not centered in the wheel.
Ouch.
I wrote a whole long spew about ways to use gauge blocks, a jeweler's vise, and so on, to try to straighten this out.
If it just wobbled in and out, that might work. But since it wobbles in and out AND up and down, I really think you need to replace the driver set.
1. Don't count on being able to find replacements unless you hunt down a whole second engine to use as a parts donor.
2. Brass engine drivers have a very tricky insulation method. Usually, the driver center is pressed inside the outer "tire", and both are conductive. So on ONE side, they put a microscopically thin layer of something like wax paper in there when they press the center into the tire so that the tire is insulated from the center (and the axle). You usually cannot see, nor even be aware, that this insulating paper is in there. This is why two brass drivers on a metal axle don't create a dead short. But when you start bending, pressing and twisting, if you move that center in or out even a hair, or rotate it even the slightest inside that tire, there's a darn good chance you will tear that fragile insulating layer and cause a short.
SECOND: What to do to fix this?
If it was just in/out wobble, honestly... I'd try something very brute force and simple.
Roll the driver set on the workbench, use calipers or a nice metal block that is the exact spacing you want between the driver backs, to accurately spot where the widest spot in the wobble is, and then gently give the drivers a squeeze together at that spot. Then roll and try again, iteratively chasing the wide spot around until you get it down to where it's acceptable. Then put a drop of red Loctite at the axle/driver joint and hope it will get into any gap, harden up, and keep the wheel from drifting cock-eyed again.
But since it also wobbles up and down - forget it. Either the center hub hole is egg-shaped, or the hub is bent,
or the whole driver center is bent, or the axle itself is bent.
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Can you measure the driver with calipers? In HO Scale, there are actually quite a few places to buy nice replacement steam loco drivers.
Try here:
http://greenwayproducts.com/greenway-products/wheel-sets-trucks-and-drivers/replacement-drive-wheels/page-4/They make ready-made driver SETS - drivers already mounted on an axle with bearings and a gear.
They are very vague on the size of the bearing blocks and gear, so I would measure your gear diameter with calipers and count the number of teeth, as well as measure the driver diameter, and then just call them to see if they have an exact match for what you need.
Honestly... that's would be my first approach.
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Grrrrr.... How I wish somebody made such a variety of steam locomotive parts like this for N Scale!
