RailKing 1:32 scale
I would expect anybody who has reached this page to be aware of most of the common scale/gauge combinations that are commercially available to the railway modeller but, just in case you were not, or if you want to see some justification for the "correct scale for gauge 1" statement then here is a very quick outline.
Model railways are riddled with odd scale/gauge combinations and mixtures of metric and imperial measuring systems.
If we start with O gauge fine scale then one would expect a scale of 7mm on the model for every foot of the prototype. This gives a scale ratio of 1:43.54 (the connection between Hornby and Dinky may help to explain why one of the most common scales for diecasts vehicles is 1:43). The trouble starts when one multiplies the scale by the gauge and taking the accepted O gauge of 32mm one ends up with either 4ft 6in (using 1:43) or 4ft 7in (using 43.54). Half O would therefore be 3.5mm to the foot at 1:87. The continentals and americans did not do at all badly with Ho, it scales to 4ft 8.57 inches. Apparently Ho scale gave problems for the early manufacturers of british locomotive models who went for 4mm to the foot (1:76.2) on the same 16.5 mm gauge, which represents 4ft 1.5 inches only (and which in turn led to the call for more accurate standards such as "protofour"). In retrospect the stupid thing is why O gauge was simply not set at 33mm, which would have given the same proportion as Ho. The answer to the obvious question has to do with the imperial measuring system, 32mm is 1.26 inches or just 10 though over an inch and a quarter, tolerances on the early models easily allowed for variations in tracklaying.
As for gauge 1? Well regardles as to whether it is finescale standard gauge or "G scale" narrow gauge the rails are expected to be 45 mm apart. Needless to say there are gauge 1 enthusiasts who love the mixed metric/imperial system and in this instance (standard gauge) it is 10 mm to the foot. If one takes the 10 mm scale (1:30.48) one would end back up with a gauge of 4ft 6in. If one takes 1:32 scale then one ends up with a gauge of 4ft 8.7in, which along with Ho is the most accurate result yet mentioned. In terms of the early standard of track you may also regard 45 mm as being just 21 thou over 1 and 3/4 inches.
Please understand that this is not intended to "flame" anyone who likes the other scales. If you are currently running one of the G scale brands then that is fine by me, similarly if you want to mix scales on the same gauge as long as you are happy with the result. If there is a point that I wish to get across then I suppose it is this: If you aspire to the finer gauge 1 scale models then these will probably be to 1:32 scale, and if you want the locomotives to look in proportion to the rolling stock then it makes sense to keep to the same scale.
If your experience of american outline rolling stock has been the 1:29 scale Aristocraft or USA Trains models then you may find these images instructive (quick comparative dimensions of the MTH model boxcar gives a height of 142mm, rail to walkway and a width of 91mm versus 160mm and 105mm for the Aristocraft model)
1/32 scale M1a (now that is a decent finescale model) with an MTH boxcar, compare height of boxcar walkway with doghouse cupola on tender. To my eyes this does not look too stupid for height or width.
Whereas........
I'll concede that the MTH stainless wheels look too shiny compared to the plastic Aristocraft ones, a bit of paint would do it.
Another height comparison against the cab of an Aster K4
I suspect that you have got the idea by now
