There are many prototype railways with 10.25" (260 mm) gauge. I'm always interested in corresponding building reports, actually this one
over at the Buntbahn Forum heavily attracts my interest. I simply could no longer resist and built a small wagon in 1/16. This wagon had to be a little bit smaller than the ones I built recently with a prototype gauge of 430 mm. It is supposed to run on 16,50 mm (16,25 mm) gauged track, representing 10.25 gauge. Therefore I mounted an additional rail (between the two present rails) on my test section to get the necessary gauge of 16,50 mm. Rails, track and radius match prototypes. I eventually put my hospital supply railway layout on hold and gonna use my actual micro layout building a ridable (miniature) farm railway in 1/16 scale with a prototype gauge of 10.25" ...