I have seen a number of references on the net (not here) since the above were introduced stating that they are not N gauge but 1/120 scale (TT120) to run on 9mm track. The opportunity came up to buy one but on receipt it does seem to be N gauge. If anyone can give me a definitive answer on this I would be grateful.
The issue is that whilst "N gauge" is understood worldwide as 9 mm gauge, "N scale" changes whether you ate in the UK (1:148) Europe and America (1:160) or Japan (1:150).
Being a Japanese model of a Japanese prototype (albeit UK built iirc) I suspect it's scale should be 1:150, but given that Japanese Railways are 3' 6" gauge then a scale of 1:120 would be more accurate for a 9 mm gauge model (would scale up to 1080 mm as against 1067 mm of the real thing).