Why Not Try 7mm Narrow Gauge 0-16.5.

[Mountain Goat]

No doubt many of you have already seen the fun I've had in this scale and gauge. I've found it real budget modelling which one can enjoy and also fit in quite a small space.
While I'm not saying it is for everyone, but I am saying that you dont really need any special modelling skills to make it work for you.
Photo shows a Hornby Smokey Joe type saddle tank converted into 7mm scale narrow gauge.

[LC&DR]

I attend a club affiliated to the O Gauge Guild and they are building a test track and hold running days from time to time. I have already taken some fine-scale Gauge O standard gauge models along, but they are now considering laying On-30 tracks to complement it. I am sorely tempted to add some 7mm/ft narrow gauge to my collection as it might be a good way of turning those 'Club' locos one gets whether one wants them or not into something a bit more interesting. Mountain Goat's 'Smokey Joe' conversion looks like a good way, but I am looking now at the Hornby GWR 101 tank as potential source. We shall see!

[Mountain Goat]

They have the same under chassis. Smallbrook Studio do a kit for the GWR 101 type shunters which uses the body as a donor loco. It doesn't look too bad but I feel the front of the boiler barren and smoke box could do with being a wider diameter. You can get away with it a bit more with the saddle tank.
The GWR 101 chassis will actually fit several of the Smallbrook Studio 7mm narrow gauge kits.
I have one or two spare GWR type bodies. I may end up with a spare saddle tank body in the future if I build the other kits I have in the drawer! Not sure yet though. See how things go.

Something to mention. The chassis with the pistons are generally more useful.
Triang chassis use the same wheelbase so the con rods are the same length etc. The axle diameters are only very slightly different so modern wheels can fit the older chassis. Triang chassis doesn't have cylinders though, and one also needs to make a new wheel pickup plate and pickups if one uses the Triang chassis with modern wheels, gears and motor. The motor can be placed in the Triang cradle via a cable tie to hold it in if I remember correctly how I did mine for my loco number 1.