Seems a lot of dosh for those days?!
A bit of research.
$70/week..$3,640/annum
US inflation 1942 to 2018. 1437.1%
$3,640 is now $55,950
In 1942 $3,640 @ US$4/£1 would be £910/annum
In 2018 $55,950 @ US$1.35/£1 is £41,350/annum
A reasonable going rate for an instructor.