Piston Ring

I have a Traxxas Nitro Sport with an aftermarket Fantom FR 15 racing engine, and it needs a piston ring.. The previous owner ran it with the wrong one and it fried off... All I need is the piston ring, but I cant seem to find one anywhere.. I looked on fantomracing.com and all they offer is the whole piston/sleeve set or a complete rebuild for 90.00.. Does anyone have one for a fantom FR 15 that they are willing to sell, or a place to get one...please help...I will be willing to trade my car for a monster truck sor something similer...
Thank You in advance.

yeah about that piston ring.... .15 engines don't have them. so now u can stop looking for one.