Welcome to KnittingHelp, Nigel!
What a lovely idea and what an adventurous knit. Making the initial swatch was an excellant idea. Read through the pattern to get an idea of the steps and the overall pattern.
Generally, with Vogue patterns it’s a good idea to check for errata although I’m not sure they maintain vintage patterns on the website.
You might also check for comments on Ravelry.
What is the name of the pattern? It’s a very pretty sweater.