I tested it with several preview and review discs - everything is fine with reading and loading. It's not custom modded regular PlayStation with printed DTL sticker. It's real grey Debugging Station. It looks like Sony didn't like to show blue Debugging Stations to public so grey systems were assembled to use at E3 1996.
Sony did the same for Japanese trade shows. If you have any questions, please feel free to ask! The item "PlayStation Programmer Tool Debugging Station DTL-H1001 GREY UNIT from E3 1996" is in sale since Sunday, August 25, 2019. This item is in the category "Video Games & Consoles\Video Game Consoles". The seller is "psx-collector" and is located in Moscow.
This item can be shipped worldwide.