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
