I really love this series of coins. The history on these is as much as you are willing to learn. Now let me loose in this thread and I could go on for hours. Let me jump start this with one of my favorite variety coins because I am, at heart, a variety coin collector. First a little history.
1817
As we know, the mint suffered from a devastating fire in January of 1816 and was partially destroyed. There were no CBH's minted in 1816 and the following year 1817 the mint only produced the large cents and the CBH's. Add to this the disruption in supplies from the War of 1812 and you can see times were difficult at the mint. To put another time stamp on this time period, 1817 was the year the Erie Canal in upstate NY was started.
These coins are history.
Two major over dates are known for this year, one the 1817/4 of which only a handful are known to exist and command 6 figure plus price tags, the other being the 1817/3. This coin is one of my favorite over date coins as the over date is so prominent even in lower graded coins.
Here is the 1817/3,  O-101a

Let me just add that these coins were all minted on a screw press until the year 1836 when the CBH were first struck using steam power. Prior to 1836, these were all screw press coins.
Imagine that - a screw press.
Not to get too far off topic on this CBH thread, but here is a very early depiction, actually the first depiction I am aware of, of a steam powered press on my 1814 Withymoor token.

Great one to start out with


I was told this is  an O-117 R4+  VF20 I bought it about 2-3 years ago for my type set and it cost me $80
I think I did ok on the price

Hey Stef, Yea I would say you did pretty good on that one
R4+ coins are hard to find.
Here is another nice over date
An 1829/1827 O-101
One thing neat about this over date is the 2 is a curl based 2 over a square based 2.

Out of all the US coinage, I do like the Bust Half the best. Very nice pieces 

I love this series.
What a beautiful coin Irwin.
Here is a real tough one to find.  This is the 1818 O-115a an R4+ variety.
This die marriage was struck using Obverse Die 12 and Reverse Die F with
the obverse die obviously breaking up.

Two neat 1811 varieties, the small 8 and large 8.

Here is an 1820/19  O-102
Notice the variety characteristics on this piece. The central obverse design (ear/hair/clasp) are all weakly struck yet look at the strong peripheral strike on the stars. This series is tough to grade without knowing the series and even the big TPG's commonly get these VERY wrong.

Wow JRocco, great stuff.........keep em coming