Help With Plating 10s

I am trying to learn as much as I can about US classics so that I can improve my skills both as a collector and as a seller. One area that I am very weak in us plating. I recently bought a small collection that I am breaking down. It included these 4 stamps that the previous owner/dealer and the auction house listed as two 10s and two 10As. Because there are so many misidentified stamps of these two I want to be sure. So I have two questions.

1) Can you help confirm or refute the ids of these?
2) If I want to be able to do this myself where do I start? Is there a good site to help explain how to go about plating 10s and 11s? It seems like a daunting task.

Thanks in advance.

Rick

By breaking it into 4 pictures I was able to upload some better quality versions:

From color perspective, top 2 look like Scott 11... bottom 2 maybe Scott 10a... hard to tell colors on scans and without dates in cancels, may have to plate these? Look forward to hearing from the experts. I hope they are not all 11s

http://www.stampsmarter.com/ also the USPCS site.
And of course THE book, The 3c Stamp of The United States 1851-1857 Issue, by Carroll Chase.

A quick look suggests to me your first stamp is an 11A from plate 3.

And judging by my monitor, your fourth stamp looks Orange Brown.

Please rlsny, do not take my opinions to the bank...so to speak. Hopefully others will offer opinions and advice.
Meanwhile, check out those web sites.

You have an 11A, 11, 10A, 10A and yes, the first stamp is a Plate 3 stamp from the famous three rows of the left pane.

If you seriously want to learn about the 3c stamp you must obtain a copy of the Chase book. It can be had regularly for under $50 on ebay.

rlsny, #4 is definitely a #10A. I'm not so sure about #3; could be an 11A brownish carmine. Any plate numbers written on the back of these?

No markings on the back of the stamps. I will continue to investigate. If anyone has any additional insight I will appreciate it. Thanks.

Just tried the StampSmarter plating links and they seem to be broken.

For example:
http://www.stampsmarter.com/feature...ate_All.html

and I will definitely keep my eye open for a copy of Chase.

Oops, bad timing on the stampsmarter site. Don is working on significant updates.
I think if you try the link here http://www.stampsmarter.com/ it will take to to a page that says server error. But the tabs across the top will work. Under the Features you'll find the 3 cent initiative.

Try this link also for the USPCS site. http://www.uspcs.org/stamps-covers/...amp-plating/