The box says 60607900 It's No Longer Available. Mine cost me $$$ on ebay, and might have been the last OEM part on the planet.
I have found that top fits better with the front end up and the latches down, top of the roof facing forward as you have it, just turned over with the front pins pointing up. It fits much better. The latches don't rub on the the surface of the parcel shelf. And if you are 6' 1" like I am, the seat leans back another inch or so and gives you more room with the roof stowed. The Ferrari photos of the period (brochure photos and the like) show it with the pins up.
The top cover fasteners are called Tenax fasteners World Upholstery has them: http://www.worlduph.com/material.htm#FASTENERS They have roof and door seals for the 328 as well.
