Kit or ?

the only clue I see that I can identify (as a non-expert) is that the bolster on the trailing truck looks like bolsters I had on some Lobough trucks.    It also looks installed upside down.    This might mean someone did some custom work to get it to fit.

Lobough did make a kit for a UP challenger that was still available into the late 50s or 60s.     That might imply that some or all of the mech was from a Lobough kit.

You would have to turn the frame upside down and take a photo to ID the mechanism.  Boiler will get you $8/lb at the scrap yard, but save the domes.

Those appear to be Lobaugh cylinder blocks.

No - I can see enough.  Not Lobaugh.  Probably all scratch built.  If it runs smoothly, save and restore the mechanisms.

Thanks guys.  I would have been concerned if any modifications to be made might ruin an otherwise stock example of a manufacturers kit.  The varying degrees of component quality lead me to believe this wasn't once a complete box of parts offered commercially.

The mechanical construction seems very sound.  Axles ride in sprung bronze journals within nicely machined steel frames.  Quartering appears good with no notable rotational binding.  Driveshafts ride in ball bearings.  The upside down cross frame on the trailing truck was an attempt by someone to gain clearance around the rear frame, I suspect rather than notching the steel.  Note the tops of the truck bolsters are also ground down at the rear for the same purpose...none to successfully.

Where to take this project is a dilemma.  Not too many, if any Challengers had spoked drivers as on this model and earlier simple articulateds had drivers much smaller than the existing 78" .  Perhaps 2 models from one?  No doubt, this ain't no weekend project.

Bruce

Although the prospect of producing a prototypical Challenger from the existing bones seems unlikely I soldiered on none the less.  The front engine is now mechanically sound after much exercising with the Dremel, well placed shims  and plain old elbow grease.

Prior to today the advise to scrap the boiler/cab shell seemed logical.  Upon disassembling it became obvious that the cab was actually made of stamped sheet...not a home made cut out concoction.   A little resoldering then a good scrub produced this.  The same will happen to the boiler and, fingers crossed, it turns out as satisfactory.

Bruce