Just received the May issue of MR and there's a good article on installing these air hoses

Wow! Hub caps on a locomotive?

Anyone else who has one of these 2-6-6-2s feel free to chime in.

After rereading your post on the best way to lube the spectrum 2-8-0 got to wondering if you had the Bachmann 2-6-6-2 and had ever attempted to lube it using the same method ?
actually had the boiler off mine for a bit of kitbashing but didn't even think of this at the time.

Kadee or intermountain make quality 36" wheelsets that should fit these cars just fine.

Seems to me some of the BLI locomotives also have this feature and they are DCC.

LABELLES has a line of model railroad lubricants including grease for gearboxes

Ok HO scale.
You said it did run at first so the following may be your best bet.
there won't be any switches or such or batteries' as a set I assume it to be DC only not DCC best bet wouldbe to contact Bachmann service Dept. Though I'm not sure of their policy on sets hopefully you can just send them the enginefor repair or replacement.

which scale ? if its the large scale the water hatch on the tender should open that's where a 9v battery will go.
also the smokebox door should open and you will find a switch inside.

LABELLES make a line of lubes that are meant for model train and are plastic compatible.

Pretty sure they were only done in brass.

Yep kit bashing can be fun,finding the latest Bachmann Mogul with DCC and sound and that it did look similar to a small Santa Fe kettle  went ahead with a few changes
.Change the coal bunker to a oil bunker added air lines to the front pilot and digging in my parts bin found a nice looking single chime whistle to replace those sad little plastic nubs on the steam turret. I then found a nice set of Champ Santa Fe decals in a more correct white and got rid of the incorrect silver lettering.
over all she came out a huskier looking little engine with I think a very pleasing look to her....now for some light weathering.

Worse case you'll have to swap the boards between the tenders

Much safer to use wash away a product by scale coat or microsofts micro sol. These used sparingly should be safe and not harm the plastic and hopefully the paint underneath.

OUTSTANDING! Loved it
With some of the absolutely assinine commercials on television these days this would be a pure breath of fresh air.
This needs to be broadcast nationwide by Coke.......