Alienware 17 R1 corner sections missing

Aug 27, 2018
Hi. I already have an Alienware 17 R4, but recently picked up an old 17 R1 for my kids. For some reason, the R1 is missing the rear corners on the case (have attached pictures).

Left corner.jpg Right corner.jpg

Can somebody please tell me how I go replacing these? (i.e. where do I get them from) .. or do I need to replace the whole base?

Any help would be greatly appreciated.