You could try eReplacementParts.com, they are located in America and they ship worldwide. I have used them before to purchase parts for my old husky 125LD weedeater, was impressed with their range, delivery time and cost. For one part it maybe cheap enough (especially it it's small and can fit inside an envelope), but you will probably get stung for delivery (perhaps $10-$15 for delivery + cost of the part).
Otherwise you could try your luck on ebay. Maybe even model the part in CAD and get someone to print it out on a 3D printer. Be sure to make a few copies!
