Doing Sums.
airborne artist, Fareastdriver, sycamore and Chugalug,
All spot on, of course ! (Are we sure that Junior didn't give Gran/Daddy a hand with the homework - or vice versa ?)
Chugalug, yes the US was still with mph and Statute miles in those days.
(I award him Bonus Points for Showing All his Work !)
Fareastdriver, 16 miles/inch is a scale I hadn't seen much, but it gives exactly the same approximation to 1:1,000,000 (from my data). Never noticed that before. Just shows, there's something to learn every day.
My thanks to you all for rising to the bait so promptly !
Danny