Champion is a brand name of the now defunct retailer FOCUS diy.
Early chamion mowers where supplied by Lawn King Trenchex. Later machines were sourced directly from China by Focus themsleves to their specification, so it is unlikely you will now get spares- unless it's parts for the engine you require and the engine fitted is from a recognised manufacturer such as briggs and stratton or honda.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix lawn mowers.