These are two nicely made pinholes. I measured them and as near as I can tell, one is .38mm and the other .40mm. I looked online and the ideal focal length for the .38mm is 72mm and for the .40mm is 81mm. I see that the metal is not completely flat, but assume it can be flattened.
$10 for the pair plus 2.00 for US postage, $5 for overseas.