Here is my novice attemp at plating these two penny blacks. Quick links: main page / FB specimen / KL specimen / attempt at plating / design highlights

I use the Stanley Gibbon Specialized Catalogue Volume 1 (GB Victoria), pages 51-70. I first find out which range of plates apply to this stamp. Most of the dies in plates 7 to 10 have the "O" flaw, in which some of the black printing is missing between the O and N of ONE, and most dies for plate 11 have the "7 o'clock ray flaw and top line break" in the star design. Since neither of these characteristics are found in either of these specimens, I start off with the assumption that both specimens are from one of the plates in the range 1 to 6. Most dies in plate 5 have slight bulging under both sides of the O of ONE, and the FB specimen has this characteristic. I conclude that this specimen is most likely from plate 5

To the left is a detail of the O of ONE for the FB specimen, showing bulging below both sides of the O, as is typical for specimens from plate 5.

I sent a link to the page to the mulready Yahoo user group, which I highly recommend, and two knowledgeable members corrected the above plating exercise to plate 6, and NOT plate 5. Interestingly, this specimen has a "6" penciled on the back. A great web site recommended to me is The Penny Black Plating Project. The plating described below for the second specimen is also incorrect. I have kept it to illustrate how difficult this process is for the novice.

Below are details from the KL specimen. This specimen proved more difficult to plate. It is not plate 5 or plates 7 to 11. Plate 4 shows many black spots over the design and plate 3 has distinctive check letters that do not match the KL specimen. We are left with plates 1, 2, and 6. The corner stars on plate 1 (both stages, 1a and 1b) have circular and small center dots, and the left star is missing the five o;clock ray and has a longer 7 o'clock ray. Neither is the case for this specimen. In addition, most dies in plate 2 have left corner stars that are sharper than the one found on this specimen. We are left with plate 6 as the most likely plate used to print this specimen.

According to the members of the mulready Yahoo user group, this second specimen is a plate 1A example.