I have seen more then one oddball Javelin with that bubble hood or flares and other "Kaplan" stuff. He had to sell that stuff for AMC dealers when people came in and ordered it. Maybe he just had his fiberglass guy send it direct. But the rear deck lid spoilers could be ordered and I have seen one bubble hoop scoop in a brown Rambler bag with a part number on it. So you could probably order that bubble hood too.
Just like the steel 290 rods that AMC never made yet I had 15 NOS ones in brown Rambler bags at one point. They had to put part numbers on all of that stuff and then actually sell it if someone ordered it.
So I am guessing in 1969 if you wanted to run a Javelin in road racing events and went to the dealer for parts they pointed you to Kaplans race shop. Its been a few years since I talked to John Martin but he told me they did work on customer stuff to keep the lights on since AMC was so stingy.
I also dont think each of the oddball Javelins were built from the ground up by Kaplans shop.
This car..... http://www.cardomain.com/ride/3177576/1969-amc-javelin/
was a base Javelin that was shipped to Australia with a container full of race parts from Kaplans shop. For years people thought Kaplan built this car and shipped to Australia but in reality the parts were sent with a factory passenger car that was built in Australia with the parts in the container.