I remember seeing a lot of Maco Corvettes over the years as Motion Performance sold the body kit to build your own Maco
John Silva , who was a Corvette customizer from Ma. built the first Maco Corvettes
They were said to be made from a thick heavy fiberglass
Silva and Motion worked together on some , then Motion began making his own Maco bodies
according to this site, the first 3 were Silva bodies
they say Motion built 3 complete Macos but sold a bunch of kits
there are some pictures here
http://www.makoshark2.com/history.php