Help!

[keagy]

My boxed rocker end cap (rear passenger side piece) fell off during spirited driving. My local dealer had the original part number listed for a '89 slantnose, but when the part was delivered it was the smaller end cap found on the Carrera. It may be that my end cap is an aftermarket design as my car is a conversion. See pictures of the driver side rear end cap which I still have. Does anyone know where I can buy a replacement?

Thanks in advance.