Looking for Suzuki parts

Hi Folks, i know im asking for stuff other than for 1 litre plus bike here but a mate who helped me get my GS together is restoring a Suzi GT550 triple two stroke and Im helping so dare i ask does anyone know where to get suzuki or replacement parts for the GT550 crank or a workshop that rebuilds cranks so we can get this old triple air coled suzuki running again all info welcome Cheers Derek