To go on my WW1 French Artillery 60cm light railway layout a scratch built Canon de 240 TR Mle 1903.
This was a coastal defence gun that was reworked to a railway gun. The gun could be transported either on standard gauge rails or transferred to the narrow gauge rails. The gun carriage was mounted on a special wagon that had standard gauge wheels that could be retracted and this transferred the load onto narrow gauge bogies that it carried at either end. The barrel was carried in a separate open wagon with the narrow gauge bogies attached. A built on crane allowed the barrel to be lifted on and off the rails and placed onto the gun carriage. Pages 43 and 44 of http://archives.ecpad.fr/wp-content/uploads/2011/04/les-petits-trains-de-la-grande-guerre.pdf illustrate this process.
I do not know if this has been posted before but there is a comprehensive archive on allied railway guns at https://eugeneleeslover.com/ENGINEERING/Railway_artillery2.pdf
Couple of photos of the completed model on a friends layout.
