Well all you have to do is buy one of the chips, then you can use a simple machine to copy it over to another one. When shops "reprogram your ECU", they use a blank chip that only costs maybe $2, copy the program over, then charge you like $200.
I haven't programmed chips myself, but I believe its something like the same kind of tool that people who make BIOS chips for motherboards or region-free chips for DVD players...
Being in the field that MorningZ is in, he could possibly elaborate (I don't think he does bios chips etc but he's always knowledgable), or maybe swiftllamagone, or another smart computer guy here on TI.
The only thing they may have done to it is removed revlimiter. VTEC is still in the stock location, funny thing is I doubt the seller even knew that and thought a 4400 RPM VTEC point is some selling point.
I doubt a scammer like that would have the knowledge to actually program specific fuel and ignition timing maps onto it. I can't understand why anyone would want to completely remove the revlimiter but it sells phony chips I guess.
BTW, a JUN chip would have it's own part number. It would not have an OEM Honda part number printed on it.