Sorry, having a senior, 30" = 2 1/2 ft. NOT 1 1/2.
To work scale out, divide full size by model size. Which gives, as Mermod correctly stated 1/20.
So it would take 2 1/2 X 20 to make the full size.
Regards Ian.
Can only put it down to having to become bi *exual in the seventies when we were supposed to go metric.
