rogerhoglund, Power Steering Pump with Cone-Shaped Output Shaft (Rebuilt) compatibility list. You may have to find the year of the 250 to be able to compare/compatibility.
Part #: 115-460-09-80-88-M278
[ More Info ]
220 and 220D (1968-73), 230 (1969, 1974-76)
240D (1974-76), 250 (1968-72)
250C (1970-72), 280 and 280C (1973-76)
300D (1975-76),
Use the parts link below for more steering parts compatibility. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
http://www.pelicanparts.com/catalog/SuperCat/W114/MBZ_W114_SUSSTR_pg1.htm