Identifying #5A
(#5A is a Type Ib)

#5A is a Type Ib design. The design on the top and sides of Type Ib are complete. However the design at the bottom is not complete, some of the bottom ornaments have been burnished off, see the illustration above.
Type 1b can be found on six plate positions:
#6RIE and #8RIE - the bottom ornaments have been burnished slightly
#3RIE, #4RIE, #5RIe and #9R1E - where the bottom ornaments have been burnished back a little more, see illustrations below.

A strip of three showing positions #6RIE (#5A), #7RIE (#5) and #8R1E (#5A)

#5RIE (#5A)
Notes on #5A
1) There is no type 1b perforate.
2) Because they were burnished less, positions #6RIE and #8R1E are more valuable
3) A certificate is a must, never buy without one.
Why are there only six positions?
The design of this early issue was too large to allow for the accommodation of the 200 subjects onto one plate. Therefore, each position had to have some amount of the design erased to allow enough room. These erasures accounted for the majority of the types. Six positions, however, had only minimal erasure to the bottom of the design whilst the rest of the design was left complete
What exactly does position 6RIE, 8RIE etc mean excactly?
The first indicator is a number indicates its position on the plate, so 3RIE would have come from the third stamp on the plate. The number can range from 1 to 100, there being 100 stamps on each plate.
The second indicator is either the letter R or L, R indicates the stamp came from the right pane, L for the left pane. The stamp was printed in sheets of 200, each sheet was further divided into two panes of 100. Hence 3RIE would have come from the right pane as the second indicator in 3R1E is the letter R.
The third indicator can be from numbers I (1) to XII (12). This indicator is always shown in roman numerals. There were twelve plates, there are no stamps from plate VI (6) as it was destroyed before printing began (no doubt it was flawed). For example stamp 4RIL would have come from plate one (1).
The last or fourth indicator is either the letter E or L. The letter 'E' indicate an early state of the plate, the letter 'L' indicates the late state of the plate. This indicator only applies to PLATE I, as it is the only one that has an early and late plate. The early plate is the original plate. After 11 months the plate became worn and 199 of the 200 positions were recut. 113 positions on the plate had both top and bottom lines recut, 40 positions had only the top line recut, 8 positions had only the bottom line recut, 11 positions had a double recut at the bottom and 4 positions had a double recut at the top.
How many plates were there?
There were twelve plates of the 1c Franklin made, plate six was never used, probably due to it being damaged in it's creation. Most of the plates were used for both the imperforate and perforated design. Some only produced one type or the other. For instance, plate 12 produced only perforated stamps and the early state of Plate 1 produced only imperforate stamps whilst plate I late (reconstruction) produced both imperforate and perforated stamps. Plate 4 was the last of the imperforate plates to be used.
POSITION 4R1
The one stamp that did not get recut was position 4R1E, which is our #5A. After the recutting process the wear on this position is such that it is classified as a type II. Finding a 4R1L (from the late sheet) with an adjacent late plate stamp is one of the holy grails of collecting this issue.
Rescources available
http://www.slingshotvenus.com/FranklinArchive/frnkln_archv_Main.html
Stanley B. Ashbrook, The United States One Cent Stamp of 1851-1857.
Mortimer L. Neinken, U.S. One Cent Stamp of 1851-61.
The Ishikawa collection: United States 1851-1857 1 cent Blue Issue postage stamps in multiples and reconstructed plates.
PLATING #5A

Position 8RIe
Positions 6R1e and 8R1e all have their bottom ornaments trimmed
back LESS than positions 3RIe, 4RIe, 5RIe and 9R1e

Position 3RIe
Positions 3RIe, 4RIe, 5RIe and 9R1e all have their bottom ornaments trimmed
back MORE than positions 6R1e and 8R1e
Click here for a comprehensive, printable, identfication guide. Courtesy of Chris Biason (447kb)