https://www.ebay.com/itm/MEPHISTO-Lyon- ... SweR9da-Sw
The London EPROM is to switch with the Lyon EPROM. Nice proposition of the seller.
A little more Munchen S Lyon 68020:
http://www.chesseval.com/WorldChampion/Lyon1990.htm
It was also a little brother that was cheaper, a Mephisto Exclusive Lyon 68000 16 Bit
http://www.chesseval.com/WorldChampion/Lyon1990.htm
But... the most precious was the Mephisto WM Lyon (the World Machine)... This one went in Lyon to win the World Championship!
A true piece of history.
Ask me if I have it...
Maurice