Dude
Bob has/had a nice pic at the era site that I use...printed it off a while back.
The link seems to be dead right now, but I will post it in case it becomes of use for you..they did not originally show the outer pinstripe as you describe but that's easy once you have the main stripe down
From my sheet the stripes are tapered.
At the nose it is 6 inches wide each stripe and they are constantly spaced 1 inch apart. At the leading edge of the hood the stripes become 6.75 inches wide...at the front of the scoop they become 7.25 inches wide..At the top where the dash edge is the stripe is widest at 7.5 inches....now on the other side at the trunk's bulkhead it is also 7.5" ...at the trunk top lip it becomes 7.25 tapering down to 6.25 at the bottom edge of the trunk where this width continues to the bottom edge of car.
From what I know as well, the stripe do not carry over the edges of the trunk or hood also the opening's inside edges are not striped either.... The picture shows these details, but you now have dimensions.
Look for centre, make your 1 inch gap between strips and then lay out stripes in tapering widths...The lemans style pinstripe is usually a 1/4" space and then a bordering pinstripe 1/4" wide if I recall correctly..ERA doesn't show them...
Hope this is helpful
Tim
This was the actual pic page...
http://www.erareplicas.com/427man/stripes.gif
http://www.erareplicas.com/427man/stripes.htm