Interesting topic - I was ordering some stickers of the ECS website today and the changeover date for the emissions sticker was 10 Mar 70, my door sticker reads 3-1970 so I took a guess and went for the post - 10 Mar sticker. Based on some of the info here I probably guessed right?
p.s. So after posting this I went back and checked on the old rego papers and it has my car listed as sold on 07 Mar 70 - how does this line up with a build date or Mar 70, did they really get them to the dealership that quick???