[1985 CCX]

Power Surge is right on the $,

Many cars like CCX, ERA, KMS, HT, and even the new component CSX cars are patterned off an original. Replicas that use donor parts are usually a bit more altered. HT are probably the most accurate Replica, aside from KMS and CSX, since they use the most correct frame.

ERA used a street CSX3252 (427) and CSX2345 (FIA) for their molds. Contemporary used CSX3045, Hi-Tech CSX3190, and as for the others I can't remember off hand.

Most cars are pretty close to their molds and yes even ERA are slightly different as is CCX. All originals are slightly different anyway since they were all hand built.
Jeff