was reminiscent of the Ferrari 330 GT 2+2 (also a Tjaarda design), but without taking away the distinctive personality of the 230 SL. Inside, Tjaarda left the dashboard unchanged, but the interior as a whole exuded the stamp of elegant Italian hand craftmanship. The result was appealing but not convincing enough to go into production and remained a one-off, subsequently acquired by German press baron Axel Springer. W 113/12 Mercedes-Benz Chief Engineer Rudolf Uhlenhaut liked pushing the power envelope of his cars. In 1965, he fitted a 250 SL with the massive M100 V8 engine from the Mercedes-Benz 600. This engine conversion gave the car, denoted as W 113/12, impressive power, but made it very front-heavy, so that this direction was abandoned. The car was eventually destroyed, the usual procedure for test vehicles at the time. Frua Shooting Brake In 1966, the Turin coachbuilder Pietro Frua, a prominent car designer in Italy in the 1960s, presented a coach built 230 SLX Shooting Brake version of the 230 SL. R 113 W 33-29 In 1968, Mercedes-Benz fitted a 280 SL with a M50F Wankel engine, denoted as R 113 W 33-29. With a top-speed of , a 0-60 mph (97 km/h) acceleration time of 8.7 seconds, and almost inaudible compared to regular SLs, it provided quite a surprise encounter for their owners in southern Germany at the time. Timeline The model timeline and production numbers are: {| class="wikitable" style="text-align:center; width:50em" |+ Production numbers. |- !Model|| Chassis || Engine || || 1963 || 1964 || 1965 || 1966 || 1967 || 1968 || 1969 || 1970 || 1971 || || Total || US |- !| 230 SL | W113.042 || 2.3L M127.II I6 || || 1,465 || 6,911 || 6,325 || 4,945 || 185 | colspan="4" | || || 19,831 || 4,752 |- !| 250 SL | W113.043 || 2.5L M129.II I6 || | colspan="3" | || 17 || 5,177 || 2 | colspan="3" | || || 5,196 || 1,761 |- !| 280 SL | W113.044 || 2.8L M130 I6 || | colspan="4" | || 143 || 6,930 || 8,047 || 7,935 || 830 || || 23,885 || 12,927 |- | colspan="13" | || || 48,912 || 19,440'|} Motorsports Spa-Sofia-Liège Rally In 1963, Eugen Böhringer won the 6,600-kilometre Spa-Sofia-Liège Rally (Belgium to Bulgaria) on a race-modified 1963 230 SL. This vehicle was thought to have been destroyed for a long time, but