Simplified "Under Sea War-Car" Copy, Made In Hong Kong by Unknown

Pretty sure it's a simplified dumbed-down hollow plastic copy of this vehicle by LP Toys:

http://www.triangspacextoys.info/SpGAderv/LPHK/LPhkLgTy/LPSeaCrt/LPSeaCrt.html

A painted version of this pix was shown at an art exhibit focused on art with Asian influences.