On the Bachmann cars I've stripped, the paint comes off easy enough with an overnight soak in 91% ISO.
How to remove the stripe and leave the black underneath, I don't know, and I would be interested to hear how others do it.
It may be less of a challenge to just completely strip it and start over seeing that you're going to custom paint it anyway.
How are you using Comet as a stripper?
Dry? Paste? How are the results?
I'm wondering if an old airbrush could be made/modified into a mini soda blaster?

I agree with Country Joe, the number of different pieces available in Unitrack make it much more versatile track system over its competition.
Bachmann continues to add pieces to theirs, and hopefully there is more yet to come.
Atlas got into the game late, and has lot's of catching up to do.
With Kato and Bachmann, the plastic roadbed track is the only track system they offer, not so with Atlas.
I don't like the track/roadbed to stand out on the layout. I'd rather it to be inconspicuous where my eyes are not drawn to it, but rather to the train itself and/or the scenery and structures instead.
The naked plastic tends to draw my eyes.

The best track for you is the one that most closely meets your requirements at a price point you are willing to pay.

That said...

Atlas, Bachmann and Kato can all be made to run flawlessly.
Turnouts may require minor tweaking.
I would rate the three equal as far as reliability, performance and electrical continuity.
I have not had any gauge issues with any of them.

A few issues I've encountered with all 3...
Flatness (vertical bowing) of rails.
Burrs on the ends of the rails.
Limited selection of pieces.

It's not my wish to sway your opinion one way or another.
Some people like Ford, some like Chevy, and some like Toyota.

IMO the bottom line comes down to aesthetics.

Good luck with your choice.

The only pick-up problem I've ever had with mine was quickly cured with a slight adjustment of the pony truck spring. Once fixed, the pick-up is fine.
Look to Richmond Controls for a wiper kit for the tender.

http://www.richmondcontrols.com/

Good luck

If it's the early (first) version and you want parts, you are going have to find a donor.
Check eBay or a train show. They are plentiful.

I don't have that lokie.
Generally, a squeal is from a bearing or bushing crying for oil.
When you run it without the shell, can you tell where the sound is coming from?
Motor? Trucks?

Check eBay; see what the sets are selling for. Also check prices on the loco and cars by themselves. Maybe you could get more if you part it out.

For those lost parts, try some old pantyhose or an old dryer sheet doubled over, pulled tight and held with a rubber band over the nozzle of a vacuum.

You might also consider changing the trucks with the knuckle couplers already attached. To fit MT or Atlas trucks on Bachmann cars you will need to ream the bolster hole of the trucks. I've used a 9/64 drill bit, turned with fingers, with good success. The delrin plastic is soft, use very light pressure with the bit. You may find a tap handle useful here. The MT trucks can be bought in pairs or in bulk (10 pairs).

You think its frustrating now, Bachmann just released the proper size to do this with just this past year or so. We've been waiting on this for years.

Anyway... to do it you will need to get a pack of assorted small straight sections product code 44899. You will need two of the 1¼ sections from that pack.
You will also need to get a 90° crossing pack product code 44841 and use two of the fitter pieces from that as well. Those fitter pieces measure 1.906 and are sold only with that crossing not available otherwise.

2x 1.25 + 2x 1.906 = 6.312

It would be so much easier if Bachmann would just sell a 2 pack of 6 5/16in. pieces.

Both the Micro-Trains site Tony linked and the transition cars are very good suggestions.

I'll throw in a Unimate short t shank as another.

http://www.hobbylinc.com/htm/red/red51000.htm

I have not tried the new Bachmann knuckle couplers so I don't know if or how they will retro-fit.
I've converted both mine to Micro-Trains couplers.
On my Dash 8-40C, I used a MT 1164
On my Dash 8-40CW, I used a MT 1168

Good luck

I have found that relying strictly on the rail joiners to maintain electrical continuity of the layout is not good practice.
If you're building a permanent layout I would recommend the use of flex track wherever possible.
I like to solder 3 sections of flex together and solder my feeder in the middle of the center section.
If you're using any of the plastic roadbed attached track types in a permanent layout, soldering rail may be the exception rather than the rule.
If it isn't broke it doesn't need fixed.

A foam base goes a long way to eliminate expansion/contraction issues as does sealed lumber.

Good luck

If you want to brew your own...

To wipe all the axles would be best, but you could get bye just using the center most axles on each truck.
You could cobble up some axle wipers from cutting thin copper shim stock, drill or punch the shim stock for the bolster hole before cutting it.
Offset T shape with the hole where the fingers come together, odd leg is your solder tab.
The drawbar connects to the bolster, so keep that in mind when you cut your wipers.
Drill a hole in the bottom of the tender directly over where your tab is going to be. Solder some light wire to the wipe tabs, and run each up through their respective holes.
Drill another hole in the front center tender floor to get both wires out down along the drawbar.
Drill and tap some small holes in the loco frames so wires can be disconnected.
Arrange your wheelsets to where the front truck picks-up from one rail while the rear picks-up from the other.

Easy, fun, one evening after dinner project.
Most of that time is trial and error on getting your wipers cut just right. After the first ones, the rest are piece of cake.

A heat sink might serve well.

Just one of many ways to do it.
Another way is to pick-up from a coil spring riding on top of the axles and going from there.

Bachmann has made a ton of these tenders so finding a cheap guinea pig at a show might help to hone skills before putting yours under the knife.

Good luck

Hi Rob56,

IIRC, on the Spectrum version, remove the two screws on bottom in the back corners. Rear of shell comes up then slightly forward to get off.
Be careful with the wires to the tender.

Good luck

Hi ffcruzm,

The Bachmann Dash 8's run fine on 11.25r.