As there has been a lot of intense talk recently about live diesels.
Here for information is the specification and contruction of the old Wada scale 1 GP9 locomotive.
Scott Macdonald was the agent in the U.S.A. Wada diesel This link is no more unfortunately. If anyone knows what happened or where Scott is now please contact.
The price at the time I saw (the only U.K. imported) one for sale at Hadley Hobbies
in London was a scary £2400 and that was a good 12-13 years ago.
There are a number of videos on You Tube such as: