I have NEVER heard of a Paragon Mako Shark replica. Every time I've heard of an Eckler's Mako replica, it ends up being just a simple tilt front end that has an almost stock appearance.
The Motion Maco has a distinct front & rear. Just look at the
Owner's Pages menu at the different sources (Silva, Motion, Bohannon & 1 Geiger) to see the differences.
I think the Kenneth Haines car was just a Eckler's tilt front-end.
Silva is the originator of the Maco body style. The Silva kit was about 13 different pieces. The Motion molds changed that to 2 pieces (the front & the back). The Bohannon mold changed the front dips. I have only seen one Geiger, and it is just very different.