1851-57 1c Franklin Plating Resources? Where?

I would like to study the 1c 1851-57 Franklins and need to have resources that would help me correctly identify the various Franklin plate positions. Where would be the best on-line and/or other resources? For example, I was unable to find a resource that would help me identify the 58L4 position. Any help would be appreciated! Thanks, James

The One-Cent Plating Archive is invaluable: http://www.slingshotvenus.com/Frank...hv_Main.html. Also, the definitive printed work (The United States One-Cent Stamps of 1851 to 1861 by Mortimer Neinken) is available online at the US Philatelic Classics Society website's (https://www.uspcs.org/) electronic library. Joining the Society is inexpensive--highly recommended. There is also much information on plating the One-Cent 1851-61 here, including a partial database of images: http://www.stampsmarter.com/index.html The Robert A. Siegel website at https://www.siegelauctions.com/ has a power search function that is also very useful.

What resource did you use to conclude that your stamp was position 96R4?

Dudley, we used the on-line 1c Plating Archive and decided it was closest to a 96R4. My wife went through every plate that had Relief F stamps, but there wasn't a link to the 58L4 available on the Archive. We just want to make sure that we have access to enough resources that would allow us to make reliably accurate identifications. — James

You can also search the forums here for examples from all the different printing plates. In the search bar type in Plate 1 late for example. Member Jaxom has also assembled a great guide dot chart that is very useful if your stamp has guide dots. I also like to have the Neinken book in hand and think it's well worth the price if you want to get serious about this issue.

Good resources like those that have been listed are a must, but "reliably accurate identifications" will only come with a significant amount of experience.

James, your experience shows why multiple resources are necessary for this type of endeavor. The drawing for 58L4 in Neinken is right on for your stamp.

ETA: The US Philatelic Classics Society's journal (The Chronicle) has a wealth of info too. Again, joining is highly encouraged.

Thank you to everyone for your input. Dudley, I will be joining USPCS.