The 1864 L has a pointed bust. The non-L coin has a rounded bust. Here are the two in my collection of each type. Yours looks kinda pointy to me. L-type first:
I have a few rounded busts and compared to them mine looks pointy. That is why I bid on the lot because I needed 1864-L and the 1872 in the lot. I have a Indian Head cent Whitman book. Your coins look good and I can see the "L" on your 1864-L.
I think that it probably is an 1864-L because of the shape of the bust, but the standard has long been that the "L" must show, even if it is a poor representation of the letter.