Hi Walter!
I bought one of these used but in like-new condition from a German ebay seller 3 or 4 years ago for my grandkids and it is really great. I don't think it was ever released in the US but I had a good experience buying from Germany. As to the speed, I couldn't say exactly, but it moves along at a pretty good clip. I had a little trouble figuring out how to open the battery compartment - the red cover is partially hinged where it meets the control button section (as shown on page 4 of the instructions that playmofire provided.) After you remove the screw, you have to lift the red cover up toward the front in order for it to release rather than pulling back.
Also, the forward and backward arrows will turn the engine on and, if I remember correctly, pressing between the arrows turns it off. There is also an auto-off after a period of time.
Good luck with your diorama!