Aftermarket bucket seat tracks

Anybody have any experience with the aftermarket bucket seat tracks?

I need a passenger side for my 72 dart and it seems like they are unobtanium..

Found these on ebay

http://www.ebay.com/itm/1970-71-72-Dart-Duster-Demon-Valiant-Bucket-Full-Seat-Track-KIT-BRAND-NEW-/261797843029?hash=item3cf45e1055&vxp=mtr