I think that pretty much covers it Jakko. Just a few extra notes:
There is no railway modelling scale equivalent to 1/35 that I’m aware of.
Gauge one is the railway equivalent of 1/32, though it isn’t widely available in the commercial world. It is also the same as 54mm figure scale as far as I am aware, but figure sculptors play fast and loose with scale so beware…..they only care if figures are consistent between their own range.
O gauge UK is no good in our field, being 1/43. This is the same scale as Britains soldiers and some die cast cars.
Continental O gauge is 1/48 so if you are working in that scale there might be useful items out there.
OO trains are 1/76, NOT 1/72. You may see HO/OO on earlier Airfix boxes. That’s because early railway toys were built on commercially available continental mechanisms . The body cross section size of UK stock (called loading gauge) was too small to fit these mechanisms at 1/87 HO scale, so they had to be stretched to OO, 1/76, so they fitted. That’s why UK model trains run on a ridiculous narrow track gauge. Just think what a Sherman would look like if the body was scale size but the tracks were 20mm closer together…..(sorry, hobby horse alert)…..and you’ll see where I’m coming from.
That’s probably all you need Alan. Don’t worry about narrow gauge nomenclature, HOn3.5 and all that stuff, I understand it and it still does my head in. From our perspective it is still basically O, OO, and HO scales.
In the mean time, this may help?