Here are some close-up images of an 1810 O.104 that I recently acquired. It was part of a four coin lot and one could see from the images an obverse scratch and an obvious cleaning. I had her pegged for a Christmas gift to a young collector but upon receipt I was blown away by the obverse doubling!
This is a really cool thread on the 1810 but not much to help with the image posted. http://forums.collectors.com/messageview.cfm?catid=26&threadid=562291&STARTPAGE=1
Bust Half 1810 O.104 Here are images of obv & rev. This type of doubling is common on many dates but to my knowledge only occurred on the O.104 during the 1810 mintage. I've seen a lot of doubled and tripled profiles (many more pronounced than this one) but this coin's doubling on S10-S13 and date is as pronounced as I've ever seen. According to Bust Half Fever author Edgar Souders the doubling was caused by a sideways slip of the working die within the screwpress.
I agree with the machine/mechanical/strike doubling idea. These are fairly common on Bust 1/2's. But, this is an extreme example. Nice find.