Unless someone with real knowledge of the Cosworth Zetec WRC program comes along, to provide answers requires far more information.

Dimensions in mm to 2 dp.
1) Skirt diameter
2) Pin diameter
3) Compression height
4) Crown volume.

AFAIK Cosworth made rods, pistons, blocks, etc for 'retail' sale as well as significantly different ones for the main Ford competition engines. Sale of these ceased several years ago with stocks sold off in batches to 2 or 3 locations.

If these pistons need to be matched to rods which differ to the 4 standard length/pin diameter ones easily obtainable........using them is going to be very expensive.