There's a seller on eBay with a dozen of them listed right now -

Grandt Line offers a C&S style 4-wheel short caboose kit in O that would be realtively easy to modify to On30.  Check their web page, there are pictures of it up and you can buy a lot of the parts seperately, I've been using them on some SP/C&C and D&RGW scratchbuilds.

Something that would be relatively easy to tool up is a snowplow based on the current caboose.  A new roof to move the cupola to one end and a blade with some side wings designed to fit on one end of the body and over the sides of it, would do the job.  I was debating on scratchbuilding some parts to turn one of my cabooses into a plow.

Have to think a retooled 2-6-0 DCC would be a no-brainer, it wouldn't require much investment in new tooling. 

But I'd suggest also offering an upgrade kit for the older locomotives that would include the decoder, new wiring, tender pickup wipers and axles for those of us with existing 2-6-0s. 

I think that was the last new thing Roundhouse came up with before being purchased by Horizon Hobby.  When they added Roundhouse to their line they decided to swap around various Athearn and MDC items to make Roundhouse a line of vintage type equipment and Athearn be more modern things, as a result the Model 40 became an Athearn product, and so did the RS3. 

http://www.tycoforums.com/tyco/forum/default.asp?sectionid=0

Suggest you look at the most recent Kalmbach Great Model Railroads annual magazine, it should still be out on better-stocked magazine racks or in hobby shops.

Has features on two different On3 layouts of Colorado prototypes, both well done, and neither with huge numbers of locomotives. 

I bought mine the first weekend of November -

Just don't be like these idiots I see on eBay who bid something with around a $10 retail you can buy very easily, up to $26. 

Funny, I just started selling off my Flyer S-gauge to put the money into more On30 stuff, scratchbuilding a couple of passenger cars, and decided to redo my HO layout (which was basically benchwork with some track) as an On30 layout.  I even came up with a new what-if premise for it. 

What I may do is make some of the scenery ambiguous enough I can still run the HO trains, too.

I think the OF 4-4-0 could become a 2-6-0 or 2-6-2 just by tooling a new chassis - it might not exactly match a Baldwin catalog engine, but it would look right. 

Peco and Micro Engineering both make flextrack and switches with wider, more greatly spaced ties to represent O scale 30" gauge track.  If you poke around you can find the Peco for $8 or so a section.  The price on all track seemed to spike when the price of metal got high over the summer.   The ME turnouts are a little cheaper.

Some guys just hand-lay the track for a scale appearance, but I've never priced that out to determine how it compares. 

Found this by accident -

http://www.girr.org/girr/relics/wp_relics/wp_relics.html

Wonder if the loco in the last picture is one of the ET&WNC 4-6-0's? 

Sounds like what's needed is uninstalled gears so that one can take some of the interference out of the fit to prevent that split issue.

On the bright side, that's a problem that's existed for years, the Athearn 1960's era HO USRA 0-6-0 suffers the same issue almost univerally -

As long as no one changes the programming in the DCC chip; I changed the address on mine and found it no longer would run on regular DC. 

I now have three cars that all came missing the part bag with the couplers, cover plates and screws - a PRR box car, a tank car, and a caboose.  I think they're all older run cars, the tank car I know I've had for several years. 

I just wondered if I need to buy those from the parts department at this point, or if I can get them sent no charge.  The couplers are no real loss, the plastic ones are too flimsy for these cars, but the screws and covers would be nice to have. 

Have to admit it would be nice if you can buy parts.  If I could find a Forney that took a header or something for a cheap price I'd buy it just to use to kitbash into other things.  Still debating what drive to fit to my plastic CP Huntingdon 4-2-4T, maybe it will become another 2-4-4T instead.