You won't find the 26 spline disk listed for the 240 stateside because it was only put in the euro 240.
The US 190 had a 26 spline clutch that is the same size and may work. There appeared to be a difference in the vibration dampning springs on the 190 disk so I didn't try it on mine, though I would have if I hadn't needed the car up and running so badly. I ended up ordering mine through the classic center and paying dearly for it.

__________________
1985 300 TD 448K
1984 300 TD 278K

1983 240D euro 240k
1994 f-250 idi turbo 330K
1986 f-350 IDI
1987 F-350 IDI

1985 JD 1050 4wd
1965 IH 3660