I have spoken with customs officals in the USA who have had these crushed as they came in with out proper paper work. The paper work claimed that the new bikes were in fact old bikes. Even with false paper work the bikes still need to have DOT aproved wheels, tires, brakes, lights and more. To bring them in legal with out "fake" paper work they also need to meet EPA regulations. So while you may be able to bring them in some ports at others they will crush the bikes. Port of Seattle would have them crushed. Port of Tacoma less then 50 miles away more then likley you would not have problems. I have found this to be the case just bringing in sidecars. In the case of the sidecar. If the lights are installed on the sidecar no problem as lights are not required on sidecars. If however as is the case when we use to bring in Sputnik sidecars, if the lights are shipped with the sidecar and not installed then as you could be planing on installing the lights on some thing that requires DOT aproval they will not allow importation. I have spent a lot of money on lawyers dealing with customs on these issues and even had a senetor involved that US customs pretty much told him to go away that they can do what ever they want.
Bottom line, the bikes are not coming in legaly, you might get away with it, You might not. Would it not make more sense to do this right? Get proper certification like Ural did and even a Dnepr importer (RAM) did at one time and not try and claim that they are some thing they are not?