I'm not really sure on all these 'model' wattage ratings... I am more familiar with industrial ratings.
IMO, I think the 350W would be for X amount of minutes, I don't know how long, and I don't know at what voltage they refer to. It's usually a lower voltage that they give that power rating for, so the power rating might be alot higher, depending on how they rate it.
You got a link to a motor?