1872 5c proof minor doubled die obverse. I finally decided to bring an example of this variety into my collection. It's an easy variety to find; in fact, a high percentage of 1872 proofs were struck with this doubled die (S2-1015, F-06, 3-O-III). You will sometimes see 1872 proof DDOs erroneously listed as FS-007.
This example appeals to me because it's original, very clean, and a pleasing (to me, at least) golden tone with subtle shades of green. So, after passing over many opportunities, I finally pulled the trigger on this one. The fields are not deeply mirrored -- which is typical for Shield proofs -- but there is a bit of cameo contrast.