Hi i purchased a few with the silver radio they looked like they where painted much better than yours is...they where OEM marui tanks and on the bottom of mine there was a little square plastic plate and when you pried it off it said marui under it.

Yours have any plastic plate glued on the bottom?
Yours may be a marui clone or actually made by marui but another company painted it and added the lights and funky wired pack in place of aa's...