Most likely, u have been scammed, as far as being scammed can be called. IF the cart is black, no sticker, why buy it?
To identify the cart now is almost impossible, since you told there was a TTMENU.Dat, but you claim it to be a R4. People sometimes mistake 'flashcarts' as an R4, becuz it is one of the most used names for it.. So best guess is that it might be a CLONE no, wood will not work, You should go to linfoxdomain, and check if you have any luck by looking into the firmwares listed.