How can I tell if authentic ProAc 2.5 or knockoffs


I have a chance of buying a pair of used Proac 2.5 for a good price, but there are nothing on the speakers that say the are 2.5s. No ProAc logo on the tweeter, no sticker or serial # on the back. I know there are some DIY kits out there, so I just want some inputs from you guys...Thanks.
locoli
ProAc 2.5 are easy to repeat and it was done already numerous of times by DIY-ers.
The raw materials to build them are near $400 probably including shipping and taxes if applied.
Not from a guy in a white van! LOL! This guy was getting rid of all his equipments locally. He had some really expensive Audio Research tube preamp & amp so I didn't think he would pair them with imitations. He told me he had bought them second hand from a previous owner. I was kinda suspicious because these didn't have grills nor the holes to hold the grills. He even offer to take the midrange driver & tweeter to show me the inside. The drivers were all Scan Speak & the crossover did say "Proac". The finish was maple strangely similar to the DIY kits posted on the net. I think he got ripped off from the previous seller then which is kinda sad. He wanted $1300. The cabinets must have been knock offs then I believe. Anyway I trusted my instinct & did not buy. Just a good learning experience & as the say "let the buyer beware". Thanks guys...