5470409 BE master cylinder, comes with a original GM SAE J1703 Delco Brake Fluid Lid
 

5470409 master cylinder core, comes with an original GM SAE J1703 Delco Brake Fluid lid (has some marks, see pictures)and another spare lid (newer style).
Cast date 15 (see picture) and a BE code stamp.
This came of a 1971 Chevelle, the BE code has also been seen on GTO Cutlass Monte Carlo and El Camino. But I am not 100% certain on the other applications.
$150.00 usd plus actual shipping costs from Alberta Canada.