To scale or not to scale....that is the question?

Little quiz for you, spot the difference

which wagon is TT 1:100 & which is TT 1:120?

The one on the left is TT 3mm scale, 1:100 and over 50 years old. The young upstart on the right is TT 1:120.

As you can see there is a marked difference, both run on the same track gauge of 12mm to the foot.

TT 120 scales out at 2.5mm and it is amazing what difference 0.5mm makes in the scheme of things.

Photo taken on Paul Hopkins, Exebridge layout.