I agree with Detlof option #2 & #3 for the most part. In my opinion the piece would probably handle the 120volts OK. I am all the time plugging things that say 220 on them into circuits carrying 240volts. 100 is a very strange nameplate rating. Are you sure it doesnt say 120? Just to be on the safe side a quick call to the factory couldn't hurt. There may be a multi tap transformer inside that can be re-configured to except the higher voltage. (As mentioned above)
Is the cord cap a standard polarized three prong?
Is the cord cap a standard polarized three prong?