I am restoring a 67 chevelle malibu. I can not remember is the black paint between the tail lights is flat or gloss. The car also SS under the trunk lock how do I find out if it belongs.

Here's a picture I'd taken of the original paint on my '67 before heading off to the paint shop.
The black is of the same "glossiness" as the rear trim molding above the bumper and taillight bezels.
With the lid closed, it's supposed to look like the continuation of horizontal "stripe" of the upper portion of the tail light bezels .

http://www.chevelles.com/showroom/BillsCamino/trunkedge.JPG

As Bill said... you do not want GLOSS back there.. SATIN BLACK is correct. Bill's example is one of two ways the rear panel black extended into the trunk. page 13 of the 67 Chevelle showroom brochure shows the other way.

If this car is a Malibu... it would not be black between the tailights. Just body color as seen on Bill's example. NO SS emblem anywhere ;)