Newly discovered German photos of Daimler Benz V20 Type MB 518 Diesel engines used in WW2 E Boats (Enemy Boat) / S Boats (Schnellboot).
A captured E Boat arrived at Menai Bridge in the 1950's and was inspected by Saunders Roe staff.
Schnellboot expert Kalle Scheuch suggests that the Boat I saw could not have been equipped with MB 518 engines but rather with type MB 501 or MB 511.
I assume these photos were provided by Daimler Benz as they were found in an envelope with their logo.
See this fantastic Schellboot animation HERE
More information on E Boats / S Boats / Schnellboots: