This plastic table hinge comes in 3 foot (give or take 1 inch) lengths and is made of brown polypropylene. It was used on 1970's Airstreams and other trailers of the same era. Designed for use with 5/8" thick table tops.

The overall width of the hinge when table is closed is 1-1/2" (T's in parallel).  The installation slot should be approximately .075" wide.