I know people have been asking a fair bit about them, so I finally casted the first 2 and put them together.
Here is a picture of the N scale and HO scale ones together.
The HO ones are looking more like a standard gauge variation, and the N scale ones look like the narrow gauge.
The 2 HO scale ones you see here are my first finished ones as my prototypes to show people.
Kadee couplers and self centering trucks are fitted after communicating with others in HO and I was advised that these are the best to use. Kadee is the HO version of N Microtrains which I use all the time.
There are also 2 videos on youtube to give you a view of them:
I did find out that it used almost 2kg of rubber to do the mold, and 5 times as much material to cast with than the N scale version.
Using a few 'trick' methods, I have managed to get the weight of the wagons to about 140g, which is 3g lighter than the NMRA standard of about 143g.