basically a dealer could alter anything he or the customer wanted....the real trick is having paperwork/receipts to back it up as a dealer installed item...
some dealers did complete paint jobs, speed equip was common, trim/stripes were very common, vinyl tops, etc etc....I owned a 69 Daytona once that was one of 3 documented dealer installed SIX PAKs known to exist.....the carbs were installed when the car had 17 miles on the odometer(the car is on EBAY right now)....wheels were another fairly common item installed by dealers.....
....bottom line, no dealer mods are considered correct in the restoration, UNLESS, you have documents proving it was installed on day 1....then they are still considered a gray area for judging......