[djunod]

I really only keep up with the Mako/Maco, so can't tell you much...

The valve covers that you mention were definitely available to the general public without any logo in them. So that doesn't mean much.

It doesn't sound like the original engine, even for a Motion built car (I'm no expert on that, but pretty sure it wouldn't be a used engine).

Doesn't sound like any headlight treatment that I've ever heard of for a Motion car either. Those headlights are also generally available from Ecklers.

I think you have found a random customization.