The original should be made of ABS, and it should be marked on the inside. I would hope the Brock shroud would also be marked on the inside as to what it is made of. If not, give them a call and ask...don't take "I don't know" for an answer...someone knows.
Do you have the fragments that were broken off? If so, you could glue them back together with ABS glue and then finish the outside so you can't see the repair. If you don't have the fragments, you would probably need another shroud to cut parts from and graft them to yours.
If you are not happy with the quality of the Brock shroud, keep looking for a used one from a Camaro or S10. It has been some years since I looked. Then, decide whether to use the OEM shroud and cut repair pieces from the Brock shroud, or return the Brock shroud and buy 2 used OEM shrouds (one to use and one to cut repairs from).
Do you have the fragments that were broken off? If so, you could glue them back together with ABS glue and then finish the outside so you can't see the repair. If you don't have the fragments, you would probably need another shroud to cut parts from and graft them to yours.
If you are not happy with the quality of the Brock shroud, keep looking for a used one from a Camaro or S10. It has been some years since I looked. Then, decide whether to use the OEM shroud and cut repair pieces from the Brock shroud, or return the Brock shroud and buy 2 used OEM shrouds (one to use and one to cut repairs from).