To know for sure you would have to remove the cover and look inside and see if it had the board installed, refer to the manual it shows the installation process for adding the board and you can check inside for it.
While it is a good radio the 8100 has been PLAGUED with problems.. Volume/Squelch control failure due to the surface mount sockets to the circuit board breaking off with use, its repairable though and i have a 8100 that i got cheap because it had this problem. They also have a problem with a failed PA, and the final used in them is no longer available, but you can get a substitute though its very expensive.
Not trying to say its a bad radio but it has known issues. Also looking at the picture it appears to have an N Connector on the coax pigtail for the antenna connection. All the 8100's i have seen are UHF, did someone cut it off and put on a N connector instead? Odd...
Even new in the box i wouldnt spend over $150 on this radio, MAYBE and thats a big maybe, $200. But even then for what your asking i could buy a brand new latest model, the 7900 is only $279 and has more features despite it not being a side by side dual display.
Also none of the 8100 accessories are available. Need a remote head mounting kit? Good luck buddy!! LOL... I had to modify my 8100 and make my own extension kit, they simply are no longer manufactured, and even if you can find one used the seller will want a small fortune for it.
Drop the price and im sure it will sell... Otherwise toss it on eBay you might get lucky.