This is something I don't see everyday! This one is Turner T-64. The 1871 series includes T-64 through the 60-pound T-76. There are imprint frames in black as well as ones in green for several examples from this series (although not this particular one). Turner's book lists 13 essays for the 1871 issue, but the discrepancy might be that the 25-pound essay was never used.
As far as sources, Turner's book (Essays and Proofs of United States Internal Revenue Stamps) is still available on
Amazon or through addall. Like revcollector said, there's probably an article or two out there on this series. I'd be interested to see what others can turn up.