A tuned version of the W123 series estate car, in addition to the exterior and interior modifications the Zender upgrade included a 215hp version of the DOHC 2.8 litre straight 6 engine. In 1980 the Zender version cost 125,000 Deutsche Marks when Mercedes charged 30,000 DMs for a standard 280 TE. Not sure how many conversions were actually sold.
Source: https://burritodetodo.tumblr.com/