All this talk of "cubic-splines" and "the external leg is a straight equivalent to the distance between track centers plus a standard 1/4 r.angle arc" has got me totally baffled.
Now I know why I use Peco Flexitrack.......you just bend it to fit in the available space
P.S. Did your Queen Mary brakevan arrive from Liverpool with all its wheels intact or was it on bricks?
John