Joint - cylinder head:

BMC 1H1049 (1500)       |
BMC 12H18  (1600)       | (These three numbers are interchangeable)
BMC 12H433 (1600, 1622) |
BMC AEH548 (Twin Cam)

Felpro/Payen     21183C  MGA 1500, 1600, 1622, all MGB 4-cyl
Moss Motors USA	 296-400  1500, 1600, 1622 stock type
Moss Motors USA	 296-405  1500, 1600, 1622 Felpro/Payen
Moss Motors USA	 296-395  Twin Cam  Bi-metal (CU on bottom, AL on top)

Moss Motors USA	 296-405 MGB 1962-1980, Felpro/Payen
Moss Motors USA	 296-415 MGB 1962-1980, copper