Yep Will, all my previous KTM models had the boiler attached by the screw through the stack. I did think about trying to unscrew or pop off the nozzle in the smoke box, but I just haven't had the courage to try that yet. I don't think the smoke box interior comes out, but I'll check that. Looking all around (top, bottom and sides) there are no visible screw heads........period.
Jay, this model was totally rebuilt by Peter Bassett and only the bones are still KTM and those are highly modified. Pony truck, trailing truck and all drivers are now equalized and sprung. Both the pony and trailing truck were hand made to match the prototype they attach much differently now than stock KTM trucks. The internal threaded screw in photo 4 attaches the trailing truck to lever that is tied to the equalized suspension of the drivers. This system is similar to the KTM/USA FEF-3 or the Sofue models I have. But, they don't have any hidden screws.