As mentioned, there are tons of variations in the over spray amounts, colors, over spray patterns, etc. depending upon when the car was produced, not to mention the plant. Since it's a Shelby forum, I guess we will just stick with San Jose here.
If at all possible, document and photograph the original finish before the car is stripped of that finish. There is absolutely no substitute to duplicating the original finish on the very car that is being restored! On some cars, this isn't possible. On most though, it is possible, but it usually takes a lot of patience and time.
Jeremy spent a tremendous amount of time duplicating the original underside finish on 6S033. The same was done for 6S933, and you can see how different it is from 6S033. Other than the fact that a totally different color was used, you will note that there was not near as much body color overspray.
...and here is a sneak peak at a very early production/first batch '65 GT350. Over 8 hours was spent gently cleaning the underside of a previous owners black out "detail job". The original finish was beautifully preserved underneath and will be duplicated during the restoration. It's black with an absolute ton of body color (white) over spray.