Minimum scale for the gauge seems like a good idea. I reckon it's something like 1:8. This is the loco I speak of in reference:
It certainly isn't the smallest 2 1/4 to the foot, as that would make it 20.125 inches in width, from an original maximum width of 9 foot. So it begs the question, there must be something smaller, it was 12, 14 inches in width at most. That would be much more reasonable. I await people's replies, but would also like to give thanks to all those who have contributed so far. Your input has been very useful. Thanks,
Mark