As stated above, the valve covers you show a picture of are available from Cobranda which is Tony Branda. Their website seems to down this morning.
The part number for a 289, 302, 351W is : VC241
The part number for a polished set for the 289, 302, 351 W is: VC241P
These are the natural finish, not the black finish.
Website -
http://www.cobranda.com
Telephone number - 814 942-1869.
Robert