Kayfun & Kayfun Monster - Do the parts interchange?

[Hans Wermhat]

I'm pretty sure the tank sections are interchangeable, but what about the chimneys? Does anybody know?

 

[Eitje]

That totally depends on which you have, version, manufacturer, etc
Even between two kayfuns, version X both, parts can or could not be (fully) interchangeable. There are just too many manufacturers and versions out there. Bit of luck helps.