When downloading the Mephisto pack linked somewhere on the right side and a bit down, you get several old engines in one zip, The Mephisot Amsterdam, Dallas, Roma, M-IV, M-V, some in 16 and 32 bit versions. That is great for an old Mephisto lover like me! H+G's Mephistos ruled.
Be advised though that the M-IV seems to be porked, I get an error when installing it under chessbase Fritz 11 GUI, it then seems to start, but only plays moves from the book. Once the book has ended, it calculates no moves by itself, and the match ends.
The others I tried did all work well.
You know the drill: first "define new UCI engine", then "load engine". When loading the engine, also go into the "parameters" and select "own book", else the engine will run with the last book loaded before, for example Fritz or Hiarcs or whatever you have.
Of course these old engines do not produce as much data output as modern, GUI optmised engines: no endless variation treees, popsitions value assessements, etc etc. The old engines simply lack the protocol to communicate with modern GUIs. But they calculate moves, and that'S what it is about.