Dm800hd se

Hi,
Been looking at some s/h DM800HD Se boxes on *******
Is there any definitive way of telling if it is a clone box? there seem to be so many around,have looked at photos of screws,pcb's etc etc but until you actually get your hands on the box and see it, it is a gamble.
I thought all clones had a sim card but on further reading that is not the case, I have already mistakenly bought a clone sim2.01
I have asked the guy about his receiver and he says as far as he is aware the receiver is genuine and he says the sim has A8P printed on it but even the sim cards can be Chinese fakes.:ack2: