Farthing - 1674   p527
farthing index

Charles II Farthing - Copper; 22mm; 4.9gms/75.6gr; 180º rotation

Rev, 4 over 4 in date - Obv, L over L in CAROLO

The above coin was purchased in March 2007 from an internet auction site, and to a large degree a punt was taken on it being a variety. It appears to have been buried for sometime and had been cleaned to a certain point. Furthing cleaning is on going (and I must say it is a very slow process). The close-up image below is as I received the coin, which highlights the 4 and L better in the image. Overall the coin is pitted, fortunately the pitting is very fine or shallow, and still shows some reasonably good detail. (brief history)

Another example - images courtesy Dr.Baqai

A comparison between the two coins - date numerals and the L over L

A query as to whether the last A of britania is over a B
My image on the left is not clear, like the coin itself. Under high magnification the right side of the A is shaped a little like a B, the middle indent in approximately the right position. And a slight outward (downward) curving protrusion inside the right bottom leg of the A. There is no evidence of a B on the left side of the A.
A higher grade coin may confirm if the A is over a B

 

4 over 4 Reverse - A different die has been used compared to the coin in the Colin Cooke Collection
The Colin Cooke coin has BRITAN   NIA letters spaced close together, the image above clearly shows the lettering further apart.

L over L Obverse - While there are some very subtle differences in the "images" of the obverses, this maybe due to the differences in the worn nature of the coins and/or the die used.
The Colin Cooke coin (below) does appear to have an L over L in the image, however this maybe due to the image itself. (further info when/if available) I have been informed that the Obverse dies are different (thanks David H)

image courtesy of Colin Cooke Coins (brightness and contrast adjusted)