I do not see that motor part available anywhere on the internet. It was sold multiple times through eBay but there are no active listings right now for the part since it is an older model. The one option that is available is to post on this forum here: http://www.fitnessforums.net/forum-10.html
The members on the forum have a section specifically designed for parts of fitness equipment and will hopefully be able to point you into the right direction or even have the part to sell you.
If you can take a minute and use the rating system to rate our session as 3 stars or higher and press Submit so I am credited with helping you.
I have not heard back from you in a while -- If the issue is resolved, please rate our session as 3 stars or more and press Submit so I am credited with helping you otherwise please reply back so we can continue with the issue.