This advice may be completely off the mark since I am not familiar with the engine and chassis. However, on a 300d 123 chassis the top bolt can be accessed with about 2 feet of extensions and a universal from the back of the transmission (just in front of the transmission mount bracket). On a 300d it looks as though it is impossible to remove the starter without disconnecting the steering mechanisms. However if you turn the steering all the way to the right, the starter slides out over the top of the tie rod. Perhaps similar processes apply in your case.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13