Here is a drawing of from a book published in 1944 called 'Cycling". It shows the proper placement of a crank cotter. I had been told years ago at Ben Olken's Bicycle Exchange in Harvard Square, Cambridge, Ma. that this was the proper way to set the cotters, but had never seen an illustration until receiving this book as a gift. Head follows the crank.
Two drawings from the 1939 Raleigh Catalog of the RRA Drivetrain