Interesting, rare and sometimes cheap ebay items.

[Hursticon]

"Prototype" Bat Optimus Primal

I'm slightly dubious that this is actually a Prototype. It seems to be just a Bat Primal that has had the paint removed from its head.

Entirely possible that it is a fake dude (As the red paint apps on the knees certainly give credit to your theory ), but the blue does seem "off" to me in terms of the end-figure's hue of blue... Hmm...

Will be interesting to see what it goes for though.