Hi Randy,
I have just had a look at an enlarged view of your photographs.
Question - Is the chassis including buffer beams, side tanks and footplate machined from a block of aluminium. Sorry all British terms. If they are my guesses could be completely wrong, the model might have been made in the UK and possibly even in Wales.
The gauge is the distance between the rails. G scale which is similar to gauge 1 is 45 mm or 1.75". Gauge 0 is 32 mm or 1.25"
Take care Tony.