It turns out the 1864 Indian Head is the rare L version! The following is notes about the L version.
Designer James Barton Longacre finally received credit for the design of the Indian Head Cent (five years after its introduction!) when the tiny letter "L" was placed on the lower ribbon on the front of the coin. With an estimated mintage of 5,000,000 pieces, the 1864-L is widely recognized as one of the most important varieties in the series. The 1864-L has a distinct, pointed bust so that even low-grade coins with the "L" worn off can be easily identified. The 1864-L is scarce in Uncirculated condition and Proof examples are among the rarest of all United States coins.
The finest Uncirculated "L on Ribbon" Brown examples graded by PCGS are 2 MS-65BN's. The finest Uncirculated "L on Ribbon" Red-Brown examples graded by PCGS are 2 MS-66RB's. The finest Uncirculated "L on Ribbon" Red examples graded by PCGS are 3 MS-66RD's.
The finest Proof "L on Ribbon" Brown example graded by PCGS is a single PR-45BN. The finest Proof "L on Ribbon" Red-Brown example graded by PCGS is a single PR-66RB. The finest Proof "L on Ribbon" Red examples graded by PCGS are 2 PR-64RD's.
Significant examples:
PCGS graded MS-65 Red. Ex - Ira & Larry Goldberg Coins & Collectibles, Inc.'s "Benson Collection, Part I", February 16, 18-20, 2001, lot 1093, illustrated, where it was described as follows: "Bronze, with "L"