Your Westwood has a transaxle. It has a pulley on the top that is driven via a log V-belt from the engine pulley. If you have no drive at all in any gear, it's likely that the belt has snapped or come off.
You should be able to pick up an owners manual on ebay. This contains all the information regarding belts and adjustments that you need.
phil_saunders(a)bigfoot.com
Phil Saunders
May 2009