Know what about it? AFAIK only Motorcraft makes the main arm piece (with the bushings) on the factory 2 piece design and any aftermarket is a one piece setup or only the 2nd piece not the main arm piece w/bushing. If the Motorcraft part is discontinued then your only option is new old stock to get a new 2-piece style arm if it was damaged.
Do you really need a new one or just replace the bushings on the old one IF you want to keep it a two piece design (for more caster adjustment, if you don't have some preexisting damage to require more caster than stock, you can just replace with the one piece aftermarket design plus a new cam bolt kit).