I model in 45mm (roughly 1:24). However, over the years I have also collected a good number of stock pieces in HO Scale (1:87). My solution is to use my HO stock as 1/4 Scale stock in the world of my large scale LHRR. That means that 1/24th figures and details will fit on and in the trains that run on 16.5mm track. It sure works out well that HO is about one quarter of G. (It's not perfect, as the chart below shows, but it'll be close enough. In reality, also shown below, "1/4 scale" isn't even perfectly 1/4 of standard gauge.
Hogwarts Railways #5972
The Hogwarts Express is a favorite of mine, since I am a huge fan of the Wizarding World. If I only had one tender for this train, I wouldn't have touched it. However, when I first received my train the tender was broken in several places. The manufacturer replaced it, so I have an extra to cut up. This is where the 1:24 driver will sit and operate his engine.
Santa Fe #330
After many hours or research, I can safely say that I have no idea what brand this engine is. So, I will cut a hole in the roof of the cab for the driver's head to pop out. Details will be fixed, eventually, but this engine is definitely a work-in-progress type of thing.
UP #720
Figures
All of the figures (drivers, passengers, etc) for the HO stock, and most of the details (crates, luggage, etc) will be 1:24 scale. Unfortunately, the position most drivers have to be in to operate this 1/4 scale engines is so awkward that companies just don't make the right pose. So, I'm building my own.
