Ah, Bicycling Science; a fascinating book, remember reading that years ago.
Interesting that though Moultons may have been ‘scientifically’ faster they were never taken up by those really interested in going fast.
They were legal for time trials in Britain in the days when their popularity was at its height, but weren’t commonly used, and certainly not by the fastest guys. And you couldn’t accuse people like Alf Engers of being hidebound by convention :D
One reason could be that testers at that time were obsessed with weight (with Engers setting the trend for ‘drillium’) rather than aerodynamics, and I don’t recall Moultons as being notably light.