The ED40 was built in England between 1960 and 1967. It used a Standard Ricardo Diesel Engine. This engine was used in the MF35 and so engine parts are very easy to obtain.
I have a Mk 1 ED 40 and the steering s quite erratic due to age and wear. I have so far, been unable to obtain any parts for the steering train. I would imagine that the only way to recover the Steering Box would be to employ a skilled precission engineer and a large amount of cash!
What i have found is that a lot of the steering play at speed (14mph!) is probably due to the king pins in the front axle being worn out. I did manage to get a track rod from a agricultural engineer.... we spent about 20 minutes going through his catalouges with the old one and a vernier to measure the tapers on the ball joints.
The ED40 must be VERY rare on the other side of the Atlantic because in 10 years of ownership here in the Britain i have only ever seen about 5 others!
Body parts are also impossible to obtain although i did see an advert for wings/mudguards in the Netherlands... but very expensive...
Let me know if you need any other help.... Decals are available by the way!