Hello WAQAS,
I think Dan is onto soomething here. The type of dipstick changed along the way. The change was not confined to model change (230SL, 250SL, 280SL ) but happened within the models.
Don't worry about having the right dipstick, the length and diameters of their tubes changed along so only the correct one of the three will fit.
Joe Alexander
Blacklick, Ohio