Honestly for the $20 or so plus shipping you could have the correct harnesses and compare to the charts and make everything a piece of cake, and you won't have to change it later. Add another $50 and you can have the lighting harness all new too.
I was trying to wire mine like you, just this last month, and giving in and buying the dash and generator harnesses was the best move I ever made.
This Book
http://www.snydersantiqueauto.com/2167 Has been the most wonderful thing I have bought being a Model A newbie myself.